JPH034133Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating electric machine such as an electric motor that obtains a rotational output by supplying electric power, or a generator that obtains an electrical output by applying a rotational force from the outside.

In general, rotating electric machines with a salient pole structure in which grooves are provided in the armature core for armature windings have more field in the armature windings than rotating electric machines without a salient pole structure. Since magnetic flux can be interlinked, it becomes a rotating electrical machine that is small, lightweight, and can provide high output. However, when the armature core has a salient pole structure, the armature core has a magnetically non-uniform structure, so cogging may occur due to interaction with the field part composed of permanent magnets, etc. The disadvantage is that it occurs.

To explain this with reference to FIG. 1, reference numeral 1 denotes a field part composed of an annular permanent magnet magnetized to two poles, and 2 denotes an electric machine having three salient pole parts 2a, 2b, and 2c. Indicate each child. And salient pole part 2a,
2b and 2c are opposed to the magnetized inner surface of the field part 1 with a required gap, and the field part 1 and the armature core 2
One of them is rotatable relative to the other. Symbols 3a, 3b, 3c are grooves for winding, 4a, 4b, 4c are salient pole parts 2a, 2b, 2c.
3-phase armature windings wound in concentrated winding are shown respectively.

Here, if we consider the rotating electrical machine in Figure 1 to be an electric motor, by sequentially passing current through the armature windings 4a, 4b, and 4c, electromagnetic interaction is generated with the field part 1. It is possible to obtain continuous rotational torque by increasing the rotational torque.

Furthermore, if the rotating electrical machine shown in Fig. 1 is considered to be a generator, it is possible to obtain three-phase AC signals 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, cogging force is generated when the magnetic energy stored in the magnetic field between the field part and the armature changes according to the relative rotation of the two, and in particular, the cogging force in the field part caused by the magnetic poles. This occurs due to both magnetic non-uniformity and magnetic non-uniformity of the armature core caused by the winding groove, and as shown in Fig. 2a, 2b,
2c, when both have magnetic periodicity, a cogging force of a harmonic component (matching component) that is common to both is generally generated.

To address this point, the applicant previously proposed salient pole portions 22a, 22b, as shown in FIG.
22c, a convex portion 22 is provided on the surface facing the field portion 21.
He proposed a rotating electric machine equipped with ap, 22bp, and 22cp (for example, Japanese Patent Application No. 1983-6759). Each of the above convex portions 2
2ap, 22bp, and 22cp are provided at positions shifted by (360°/number of field poles) with respect to the winding groove, and these convex portions can reduce the cogging force, but the rotation Depending on the structure of the electric machine,
Specifically, depending on the number of poles of the field part and the number of poles of the salient pole part, the part where the convex part should be provided, that is, the part shifted by (360°/number of field poles) with respect to the winding groove. To,
In some cases, the groove for the winding is located exactly, and in such a case, it is not possible to reduce the cogging force due to the convex portion.

The purpose of this invention is to use the convex portions provided on the salient poles to generate a magnetic field that is independent of the magnetization conditions of the field part and regardless of the number of poles of the field part and the number of poles of the salient pole part. An object of the present invention is to provide a rotating electric machine that can reduce cogging force.

This invention provides at least one end of the surface of the salient pole part of the armature facing the field part with a convex part that protrudes from the salient pole part toward the field part, and also provides a periphery of the convex part. The width in the direction is smaller than the width where the salient pole part faces the field part, and the width is at least 1/2 times and no more than 1 time the circumferential width of the winding groove. It is.

The present invention will be explained below with reference to illustrated embodiments. In FIG. 3, reference numeral 31 indicates a field section consisting of an annular permanent magnet magnetized to N and S poles, and 32 indicates an armature core constituting the armature. The child 32 is configured to rotate relative to the child 32.

The armature 32 has three salient pole parts 32a, 32b,
32c and grooves 33a formed between these salient poles,
33b and 33c, and each salient pole portion is provided with an armature winding 34a, 34b, and 34c, respectively.

Convex portions 32a 1 , 3 are provided at both ends of the surface facing the field portion 31 of each of the salient pole portions 32a, 32b, _32c .
2a ₂ , convex portions 32b ₁ , 32b ₂ , convex portions 32c ₁ , 32c ₂
are formed respectively.

The fourth example shows a rotating electric machine in which the field part 41 has two poles and the salient pole parts of the armature 42 have four poles.
Convex portions 42a ₁ , 42a ₂ ,
Convex portions 42b ₁ and 42b ₂ , convex portions 42c ₁ and 42c ₂ , and convex portions 42d ₁ and 42d ₂ are provided, respectively.

If the field part is 2 poles and the number of armature poles is 4 poles, the groove will be located exactly at a location offset by (360°/number of field poles) from the winding groove. Therefore, as shown in FIG. 2, a convex portion cannot be provided at the center of the salient pole portion.

FIG. 5 shows the generation of cogging force in a conventional rotating electrical machine, and FIG. 6 shows the generation of cogging force in the rotating electrical machine of the present invention.
5a and 6a show the case where the salient pole part is three poles, and FIGS. 5b and 6b show the case where the salient pole part is four poles, respectively.

As is clear from FIG. 6, according to the present invention,
The generation of cogging force can be significantly reduced compared to conventional rotating electric machines.

In the embodiment of the present invention, a structure is shown in which a convex part for reducing cogging force is provided at both ends of the salient pole part, but the same effect can be obtained even if this convex part is provided only at one end of the salient pole part. play.

As a result of the above-described configuration of the present invention, for example,
Regarding the position of each groove for winding (360°/number of field poles)
Even if the winding groove is located exactly at a position that is deviated by a certain amount, the cogging force generated by the winding groove can be absorbed by the above-mentioned method provided at at least one end of the salient pole portion. Since the cogging force generated by the convex portion having a defined width in the circumferential direction can be almost canceled out, the resultant cogging force can be significantly reduced over the entire circumference.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional rotating electric machine, FIG. 2 is a sectional view showing an example of a rotating electric machine equipped with a cogging force reduction means, and FIG. 3 is a sectional view showing an example of the present invention. FIG. 4 is a cross-sectional view of the rotating electric machine showing another embodiment of the present invention, and FIG.
FIG. 6 is a diagram showing the cogging force generation situation in the rotating electric machine of the present invention. 31, 41... Field part, 32, 42... Armature, 32a, 32b, 32c; 42a, 42b,
42c, 42d... Salient pole portion, 32a ₁ , 32a ₂ , 3
2b ₁ , 32b ₂ , 32c ₁ , 32c ₂ ; 42a ₁ , 42a ₂
~42d ₁ , 42d ₂ ...Convex portion.

Claims (1)

[Scope of utility model registration request] The field part is magnetized to an even number of poles, and the armature has a winding groove and a salient pole part arranged opposite to the field part, and the field part and the armature are arranged opposite to each other. In an electric machine in which one of the salient pole parts is rotated relative to the other, at least one end of the surface of the salient pole part facing the field part protrudes from the salient pole part toward the field part. A convex portion is provided, and the circumferential width of the convex portion is smaller than the width of the salient pole portion facing the field portion, and 1/2 of the circumferential width of the winding groove. A rotating electrical machine characterized by being formed to have a width that is greater than or equal to one time or less.