JPS61251463A - Rotary electric machine - Google Patents

Abstract

PURPOSE:To increase an effective magnetic flux while effectively preventing a cogging and to increase a torque by canceling a cogging force generated by a groove for a winding by a cogging force generated at a plurality of projections formed on salient poles, respectively. CONSTITUTION:A cogging force generated at a salient pole 22a is reverse to cogging forces generated at projections 22a3, 22b2, 22c1, respectively, thereby canceling the cogging force. Since the cogging force is canceled by the three projections for one groove of the armature 22, the cogging force shared by the three projection formed at each salient pole can be 1/3, and a gap between the position except the projections of an armature and a field 21 can be largely reduced. Further, since the number of the projections formed at one salient pole is increased, the effective magnetic flux between the field and the armature can be largely increased to increase a torque.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to electric motors that can obtain rotational output by supplying electric power, or generators that can obtain electric output by applying rotational force from the outside. Regarding rotating electric machines.

(Prior art) In general, rotating electric machines that have a salient pole structure by providing grooves in the armature core for armature windings have a larger field strength than those that do not have a salient pole structure. Because the magnetic flux can cross, it becomes a rotating electrical machine that is small, lightweight, and can produce high output. However, if the armature core has a salient pole structure,
Since the armature core has a magnetically non-uniform structure, there is a problem in that cogging occurs due to interaction with a field section composed of, for example, a permanent magnet.

This will be explained with reference to FIGS. 6 and 7. In FIG. 6, reference numeral 1 denotes a field section consisting of an annular permanent magnet magnetized into two poles, and 2 denotes an armature core constituting the armature, which consists of three ultimate sections 2a, 2b, and 2c.
has. These salient pole parts 2as2b, 2C are opposed to the magnetized inner surface of the field part 10 with a predetermined gap between them, and either one of the field part 1 and the armature core 2 is opposed to the other. It can be rotated freely. In addition, codes 3a and 3b
, 3c are winding grooves, and 4a, 4b, and 4c are three-phase armature windings wound around the salient pole portions 2a, 2b, and 2c in a concentrated manner, respectively.

Here, if we consider the rotating electrical machine shown in Fig. 6 as an electric motor, by passing current through the armature windings 4a, 4b, and 4C in order, the electromagnetic force generated between the field section 1 and the armature 2 can be sustained. rotational torque can be obtained.

Furthermore, if the rotating electrical machine shown in Fig. 6 is considered to be a generator, it is possible to obtain three-phase AC output to the armature windings 4a, 4b, and 4C by rotating the field section 1, which is the rotor, from the outside. can.

By the way, the cogging force is generated when the magnetic energy stored in the magnetic fields of the field part and the armature changes according to the relative rotation of the two, and in particular, the cogging force is caused by the magnetic non-uniformity of the field part ( The salient pole portions 2a, 2b of the field portion 1 and the armature core 2, as shown in FIG. When both 2C have magnetic periodicity, a cogging force of a harmonic component (matching component) that is common to both is generally generated.

To address this issue, a method has been proposed to reduce the cogging force by increasing the order of the harmonic components (for example, Japanese Patent Publication No. 58-42707).
. FIG. 7 shows an example of such a system.
The difference from the example in the figure is that the salient pole portion 12 of the armature core 12
Auxiliary grooves 5al, 5a2.5bl, 5b2.5cl,
5c2 was provided. In addition, each of the above-mentioned auxiliary grooves 5al~
5c2 is the rotating shaft of the field part 1 or armature core 12, that is,
It is provided in the longitudinal direction of the central axis passing through the center point A (in the direction perpendicular to the plane of the drawing).

As a result, by providing auxiliary grooves, we have essentially increased the number of grooves that cause cogging force, and the harmonic components due to the iron core will have three times the frequency if two auxiliary grooves were provided. Therefore, it becomes a harmonic component and the cogging force decreases. However, such means is effective only in a certain specific case of the magnetized state of the field part, but has the drawback that the cogging force changes when the magnetized state changes.

Therefore, the present applicant proposed a site that faces the field of the salient pole of the armature, and that is (360°/
We previously filed a patent application (Japanese Patent Application No. 59-6759) for a rotating electric machine in which a convex portion is provided at a position shifted by the number of field poles or an integral multiple thereof.

(Problems to be Solved by the Invention) According to the rotating electric machine disclosed in Japanese Patent Application No. 59-6759, the cogging forces generated by the grooves for the windings of the armature are canceled out by the convex portions, and the cogging forces are reduced. In addition, since the cogging force caused by the winding groove is directly canceled by the convex part, the magnetic flux waveform of the field,
That is, there is an effect that the cogging force can be reduced even if there is variation in magnetization with respect to the field because it is hardly affected by the magnetization state.

However, according to the rotating electric machine according to the above application, it is necessary to set the height of the convex part of the armature to a height sufficient to offset the cogging force due to the winding groove, and as a result, the concave part other than the convex part The gap between the magnetic field and the magnetic field becomes large, and the effective magnetic flux decreases, resulting in a decrease in torque.

In addition, the salient pole part of the armature has a groove for the winding (360
If the number of magnetic poles of the field is set to an even number of 4 or more under the condition that the convex portion is provided at a position shifted by 1/number of field poles, in most cases the armature will The convex portions 6a, 6b, 6c are formed not at the center of each salient pole portion 2a, 2b, 2c of the armature 2, but at offset portions, and the front and back sides of the armature 2 have different shapes, making assembly complicated. There is also the issue of becoming.

An object of the present invention is to provide a rotating electrical machine that uses the cogging prevention principle of the invention according to the above application to increase effective magnetic flux and increase torque without impairing the cogging prevention effect.

(Means for Solving the Problems) The rotating electric machine of the present invention has 2n (however, n is an integer of 2 or more) poles magnetized in the field, and the salient poles of the armature are opposed to the field. A plurality of convex portions are provided at the portion of each salient pole that is shifted by (360°/number of field poles or an integral multiple thereof) with respect to the position of the winding groove. .

(Operation) The cogging force generated by one winding groove of the armature and the cogging force generated by the plurality of convex portions of each salient pole act in opposite directions and cancel each other out, thereby reducing the cogging force. In order to offset the cogging force generated in one winding groove, the cogging force of the plurality of protrusions on each salient pole can be divided by a fraction of the number of parts. Therefore, the height of each protrusion is Compared to the case where only one convex portion is provided, it is necessary to reduce the amount by several minutes.

(In FIG. 1, reference numeral 21 is a field made of an annular permanent magnet magnetized into four poles in the circumferential direction, and 22 is an armature composed of an iron core. Two salient poles 22a,
22a and 22c. Each salient pole 22a,
22b and 22c are opposed to the inner surface of the field 21 with a predetermined gap therebetween, and one of the field 21 and the armature 22 is rotatable relative to the other. Winding grooves 23a, 23b, 23c are formed between each of the salient poles 22a, 22b, 22c.
The grooves 23a, 2a are formed at the bases of 2a122b, 22c.
Three-phase armature windings 24a, 2 through 3b, 23c
4b and 24c are wound by concentrated winding.

Each of the salient poles 22a, 22b, and 22c of the armature 22 includes a portion of the salient pole 22a that faces the field 21.
, 22b, 22c each have a plurality of convex portions 22a1, 22a2.
．． 22a3.22b1.22b2.22b3.22C1
, 22c2, 22c3 are provided.

These convex portions 22a1 to 22c3 are provided at positions shifted by 90° and 180° with respect to the valley grooves 23a7, 23b, and 23C for the winding, respectively.

Generally speaking, the number of magnetic poles of the field and the location of the convex portion provided on each salient pole of the armature are as follows: The number of magnetic poles of the field is 2n poles (where n is an integer of 2 or more), and each salient pole of the armature is The portion of the convex portion provided on the salient pole is a portion shifted by (360°/number of field poles or an integral multiple thereof) with respect to the position of the valley grooves 23a, 23b, and 23c for the windings, and if such conditions are satisfied. Cogging force can be reduced.

The number of poles of the field 21 and the formation locations of the convex portions 22a1 to 22c3 in the embodiment shown in FIG. 1 will be explained according to the above general conditions.
When n is 2 and the number of poles of the field 21 is 4, a portion shifted by 90° (360°/number of field poles) with respect to the valley grooves 23a, 23b, 23c for windings, and an integer at this 90°. The above-mentioned convex portions 22a1 to 22c3 are provided at positions shifted by 180° multiplied by 2.

Next, the cogging reduction effect of the rotating electric machine according to the embodiment shown in FIG. 1 will be explained with reference to FIG. 3. In the state shown in FIG. 3, as the armature 22 moves rightward relative to the field 21, a cogging force is generated as the salient pole 22a tries to move away from the N pole of the field 21, and at the same time , each salient pole 22 at the neutral point B, C, D of each magnetic pole of the field 21.
Convex portions 22a3, 22b2 of a, 22b, 22c
．． 22c1 is about to enter, causing a cogging force. The former cogging force generated on the salient pole 22a and the latter convex portions 22a3.22b2.22c
The cogging forces generated at 1 are in opposite directions, so that the cogging forces cancel each other out.

In this way, in the above embodiment, the cogging force is canceled out by the three convex portions for one groove of the armature 22, so that each salient pole has three convex portions. The cogging force to be shared may be one-third, so as shown in FIG.
The height t can be reduced to one-third of the height when each salient pole is provided with one convex portion as in the invention related to the above-mentioned application. Therefore, the gap between the field and parts other than the convex parts of the armature can be significantly reduced.
Moreover, since the number of convex portions provided on one salient pole is increased, the effective magnetic flux between the field and the armature is significantly increased, and the torque can be increased.

In addition, as shown in FIG. 2, each convex portion 22al~
The angle θ1 of 22c3 is the valley groove 23a, 23b, 2
It is preferable to set the angle θ2 to be the same as the angle θ2 of 3c.
~2.0)·θ2, there is no practical problem.

4 and 5 show another embodiment of the invention.

In the embodiment shown in FIG. 4, n is 4 and the number of magnetic poles of the field 31 is 8.
The armature 32 has three salient poles 32a, 32b,
32c, each salient pole 32a, 32b, 32c
A plurality of convex portions are provided for each salient pole at a portion facing the field 31 at an angle of 360°/number of field poles (360°/number of field poles) with respect to the position of the winding grooves 33a, 33b, 33c. It is an integer multiple of this.

They are provided at locations shifted by 90°, 135°, and 180°.

In the embodiment shown in FIG. 5, n is 2 and the number of magnetic poles of the field 41 is 4.
The armature 42 has five salient poles 42a, 42b, 42.
c, 42d, 42e, and each salient pole 42
A plurality of convex portions are provided for each salient pole at the portions a to 42e facing the field 41, and valley grooves 43a, 43b for winding are provided.
43c, 43d, and 43e are provided at positions shifted by 90°, which is 360°/number of field poles, and 180°, which is an integral multiple thereof.

The embodiments shown in FIGS. 4 and 5 also provide the same effects as those described for the embodiment shown in FIG.

(Effects of the Invention) According to the present invention, the cogging force generated by the winding groove at one location can be canceled out by the cogging force generated by the plurality of convex portions provided on each salient pole. The height of the convex portion can be made lower than when each salient pole is provided with one convex portion.

Therefore, the effective magnetic flux is increased due to the synergistic effect of being able to reduce the gap between the parts of the armature other than the above-mentioned convex parts with respect to the field, and increasing the number of convex parts close to the field and increasing their area. Therefore, it is possible to provide a rotating electrical machine with a large torque while effectively preventing cogging. In addition, since multiple convex parts are provided for one salient pole, the core that makes up the armature is symmetrical, and the front and back sides have the same shape, which improves the efficiency of assembly work and prevents assembly errors. You can also do it.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of the same embodiment, and Fig. 3 explains how the cogging force is reduced in the above embodiment. FIG. 4 is a cross-sectional view showing another embodiment of the present invention, FIG. 5 is a cross-sectional view showing yet another embodiment of the present invention, and FIG. 6 is a conventional rotation FIG. 7 is a cross-sectional view showing an example of an electric machine; FIG. 7 is a cross-sectional view showing another example of a conventional rotating electric machine; FIG.
The figure is a sectional view showing yet another example of a conventional rotating electric machine. 21.3L 41-field, 22.32.42... armature, 22a, 22b, 22c, 32a
, 32b, 32c, 42a. 42b, 42c, 42d, 42e - salient pole, 23a, 23b, 23c, 33a,
33b, 33c, 43a. 43b, 43c, 43d, 43e - groove for winding, 22al, 22B2.22a3.22b1.
22b2.22b3.22c1.22c2.22c3-
Convex part.

Claims (1)

[Claims] In a rotating electrical machine in which an armature having a winding groove and salient poles is arranged to face a field, and one of the armature and the field is rotated relative to the other, the field has a 2n (However, n is an integer of 2 or more) At the same time as magnetizing the pole, it is a portion of the salient pole of the armature that faces the field, and is located at an angle (360°) with respect to the position of each groove for the winding. A rotating electric machine characterized in that a plurality of convex portions are provided at portions of each salient pole shifted by / field pole number or an integral multiple thereof).