JPH0681436B2 - Rotating electric machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotating electric machine with reduced cogging force.

(Prior Art) A rotating electric machine having a salient-pole armature core has a magnetically non-uniform structure due to the formation of winding grooves. There is a problem that a cogging force is generated by the interaction, and smooth rotation of the rotor is impaired.

Therefore, the present applicant has proposed that the salient pole of the armature is a portion facing the field, and is 360 ° / the number of field poles or an integral multiple of 360 ° / the number of field poles with respect to the position of each groove for winding. We previously filed a patent application for a rotating electrical machine that has a protrusion at a portion that is offset by a certain amount.
(JP-A-60-152240, JP-A-61-251463).

FIG. 10 shows an example of the rotating electric machine according to the above application, in which reference numeral 1 is a magnetic field composed of an annular permanent magnet magnetized in two poles, and 2 is an armature core that constitutes an armature. Show. The armature core 2 has three salient poles 2a and winding grooves 2b between these salient poles 2a. The armature core 2 constitutes a rotor and can rotate around the shaft 3. When the number of field poles is P, the portion of each salient pole 2a of the armature core 2 facing the field 1 is displaced by 360 ° / P from the position of the groove 2b for each winding, that is, Since the number of field poles is 2, a projection 2c is provided in a radial direction at a position shifted by 180 ° in a direction parallel to the groove 2b. The protrusion 2c is 360 ° / P with respect to the position of the winding groove 2b.
It may be formed at a position deviated by an integer of.

According to the rotating electric machine, the cogging force generated by one winding groove 2b of the armature and the cogging force generated by the protrusion 2c of each salient pole 2a act in opposite directions to cancel each other and the cogging force is reduced. .

(Problems to be Solved by the Invention) In a conventional rotating electric machine, it is necessary to make the height of the protrusion provided on the salient pole of the armature core high enough to cancel the cogging force of the winding groove. As a result, as shown in Fig. 11, salient poles
There is a problem that the gap between 2a and the field 1 becomes large as a whole, the effective magnetic flux decreases, and the efficiency decreases. In other words, the effective magnetic flux and efficiency were sacrificed to prevent cogging. Further, as shown in FIG. 11, since the entire salient pole 2a needs to be moved closer to the central axis direction by the amount of the protrusion 2c, the winding space becomes smaller. Has a problem that it has a complicated shape.

The present invention has been made to solve the above-mentioned conventional problems, and it is possible to reduce the cogging force while preventing the reduction of the effective magnetic flux and the efficiency, and also to prevent the winding space from becoming small. It is an object of the present invention to provide a rotating electric machine that can be used.

(Means for Solving the Problems) The present invention is directed to an armature having a field magnetized to an even number of poles, a plurality of winding grooves and a plurality of salient poles arranged to face the field magnet. A rotating electric machine for rotating either one of the field magnet and the armature with respect to the other, where the number of field poles is P, a salient pole portion facing the field magnet,
Predetermined by projecting in the axial direction at a portion shifted by 360 ° / P with respect to the position of each winding groove, or a plurality of portions shifted by 360 ° / P and an integer multiple thereof with respect to the position of each winding groove When a protrusion having a width of is formed, and this portion and other portions are compared at the same width in the circumferential direction, the salient pole surface area of the portion where the protrusion is formed is the salient pole of the other portion. It is characterized by being larger than the surface area.

(Function) It is a part facing the field of the armature and is displaced by 360 ° / P from the position of each winding groove, or 360 ° / P and an integer multiple of each winding groove position. The cogging force generated by the displaced parts is larger than the cogging force generated by the other parts of the salient pole due to the large surface area of that part, and this cogging force and the cogging force generated by one winding groove of the armature Are offset.

(Embodiment) An embodiment of a rotating electric machine according to the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, reference numeral 10 is a field magnet made of a ring-shaped permanent magnet magnetized in two poles in the circumferential direction, reference numerals 10 and 11 are laminated cores, and 12
Is a yoke plate, and 14 is a rotation axis. The yoke plate 12 has a flat plate portion 121 and three winding grooves 123a, 123b, 123c, and three salient poles 122a, 122b, 122c extending parallel to the rotating shaft 14 from the outer edge portion of the flat plate portion 121. Have. The two yoke plates 12 thus formed are used, and the flat plate portions 121 are back-to-back and the salient poles 122a, 122b, 122c and the winding grooves 123a, 123b, 123c overlap in the axial 14 direction. In such a manner that they face each other, and the laminated core 11 is placed between these two yoke plates 12.
Has been installed. The laminated core 11 has three winding grooves 123 and three salient poles 111 divided by these grooves 112, and each winding groove 112 overlaps with each winding groove 123a, 123b, 123c of the yoke plate 12. , The salient poles 111 are the salient poles 122a, 122b, 122 of the yoke plate 12.
It overlaps with c. Yoke plates 12, which overlap each other,
The three-phase armature windings are wound by concentrated winding through the winding grooves of 12 and the laminated core 11 to form the armature 15, but the windings are not shown. An armature 15 including the two yoke plates 12 and 12 and the laminated core 11 is rotatably held by a rotary shaft 14 in a field 10.

The salient poles 122a, 122b, 122c of the respective yoke plates 12, 12 are arranged at the positions facing the field 10 at the center position in the rotational direction.
Protrusions 124a, 124b, 124c extending in a direction parallel to are formed,
When comparing the portion where the protrusion is formed and the other portion with the same width in the circumferential direction, each of the protrusions 12 viewed from the field 11 side.
The surface area of the 4a, 124b, 124c forming portion is larger than the surface area of other portions of the salient poles 122a, 122b, 122c. When the number of field poles is P, each protrusion 124a, 124b, 124c is provided at a position shifted by 360 ° / P from the position of the groove for each winding. In the above embodiment, as shown in FIG. 3 (a), each protrusion 12 is located at a position shifted by 360 ° / 2 = 180 ° with respect to the position of each winding groove.
4a, 124b, 124c are provided. More specifically, the protrusion corresponding to the winding groove 123a is 124b, and the winding groove 123b is
The protrusion corresponding to is 124c, and the protrusion corresponding to the winding groove 123c is
124a, the surface area of the salient pole of the portion where the protrusion is formed is the surface area of the other portion of the salient pole when the formation portion of these protrusions and the other portion are compared with the same width in the circumferential direction. Is wider than.

According to the above-described embodiment, the cogging force generated in the protruding portion 124a, 124b, 124c forming portion of the yoke plate 12 in the portion of the armature 15 facing the field 10 is generated in the other portions of the salient poles 122a, 122b, 122c. It is larger than the cogging force that occurs. In the above-described embodiment, P = 2, and the protrusions 124a, 124b, 124c are formed in the winding grooves 123a, 1
As a result of installing at a position that is shifted by 360 ° / P = 180 ° from the position of 23b, 123c, the cogging force generated by each of the above-mentioned protrusions is compared with the cogging force generated by each winding groove 123a, 123b, 123c of the yoke plate 12. As a result, the directions are opposite to each other and cancel out, and the cogging force of the rotating electric machine can be reduced.

Further, according to the above-described embodiment, since the yoke plate is used to partially widen the surface area of the salient poles of the armature, the shape of the armature core can be simplified.

A portion of the armature 15 facing the field 10 and having a large surface area, that is, the protrusions 124a, 124 in the above embodiment.
The width in the circumferential direction of the portion where b and 124c are formed is basically 12
It may be the same as the width of 1,123a, 123b, 123c, but since the cogging prevention effect is obtained even if the phase of the protrusion and the winding groove is slightly deviated, the width of the protrusion is set to the winding groove. Width of 0.4-2.5
It can be doubled.

The surface shape of the armature for partially widening the surface area of the portion of the armature facing the field is not limited to the shape of the above embodiment, and the surface shape of FIG. 3 (b) (c) (d) is not limited. It may be modified as follows. (B) a shape in which a part of the salient poles of the armature is axially projected to only one side, (c) is a shape in which salient poles divided in two in the axial direction are connected by a projection in the middle thereof, (d) Is a shape in which salient poles that are divided into two in the axial direction are connected by a projecting portion in the middle thereof, and a part of the salient poles is projected in only one side in the axial direction. 4 to 6 show specific examples for obtaining such a deformed armature shape. FIG. 4 shows a core 21a having a long salient pole and a core 21b having a short salient pole in the circumferential direction.
(A) is obtained by alternately stacking cores 21a and 21b, and (b) is obtained by stacking cores 21a on both sides of the core 2a.
1b is superposed, (c) is a core 21a is superposed and a core 21b is superposed on one side thereof.

FIG. 5 shows a combination of a core 21c having a salient pole that is long in the circumferential direction and a yoke plate 21d that has a salient pole that is short in the circumferential direction and thick in the axial direction. Stacked yoke plates 21d, (b) stacked core 21c
The yoke plate 21d is stacked on one side of the.

FIG. 6 shows a core 21f having a salient pole that is short in the circumferential direction and a yoke plate 21e that has a salient pole that is long in the circumferential direction and thick in the axial direction.

Next, another embodiment of the present invention will be described. In FIGS. 7 and 8, reference numeral 30 is a field magnetized with four poles, 31 is an armature, and 34 is a rotating shaft. The armature 31 has three salient poles.
Winding grooves 313a, 313b, 31 between 312a, 312b, 312c and these salient poles
Has 3c. As shown in FIG. 8, each of the salient poles 312a, 312b, 312c is provided with three protrusions 314a, 314b, 314c that partially extend in the direction of the rotation axis, as shown in FIG. The surface area of that portion is larger than that of other portions of the salient pole. In this example, P = 4, and the protrusions are provided at a plurality of positions deviated from the positions of the winding grooves by 360 ° / 4 = 90 ° and 180 ° and 270 ° which are integer multiples thereof. ing. That is, in this embodiment, a plurality of parts having a large surface area are provided for one winding groove. More specifically, three protrusions 314b right, 314c, and 314a left are provided for the winding groove 313a, and three protrusions 314c right, 314a are provided for the winding groove 313b. The left side 314b is provided with three protrusions 314a right, 314b, and 314c left with respect to the winding groove 313c.

Also in the case of the above-mentioned embodiment, the effect of reducing the cogging force is exhibited as in the case of the above-mentioned embodiment. And in the case of this embodiment, since there are a plurality of parts having a large surface area for one winding groove,
The ratio of the surface area of the wide portion to the surface area of the narrow portion can be reduced, and the overall length in the rotation axis direction can be reduced.

FIG. 9 shows various modifications for providing a plurality of portions having a large surface area with respect to one winding groove. (A) is a shape in which a part of the armature is projected in only one side in the axial direction, (b) is a shape in which a part of the armature is projected in an intermediate portion in the axial direction, and (c) is a part in which the armature is axially projected. The shape is such that it is projected on one side and the middle part in the direction. Various means as shown in FIGS. 4 to 6 can be used as specific means for obtaining the armature in various shapes.

The length of the armature with a large surface area in the direction of the rotation axis is basically twice as long as the other parts of the salient pole when the number of the wide parts is equal to the number of winding grooves. If the number of wide parts is twice the number of grooves for winding, 1.5 times the length of the other parts of the salient pole,
When the number of the wide portions is three times as large as that of the winding groove, it is preferable to make the length about 1.33 times as long as the other portion of the salient pole in order to reduce the cogging force. However, the configuration of the magnetic circuit such as the axial length of the field is different, and various other design conditions are also different.Therefore, the optimum dimension in the circumferential direction and the axial direction of the part with a large surface area of the armature are required. The optimum size depends on the above various conditions.

The present invention can be applied to a rotary electric motor and a generator. Either one of the field magnet and the armature may rotate with respect to the other, and the outer rotor type or the inner rotor type may be used.

(Effect of the Invention) According to the present invention, the surface area of the portion of the armature facing the field is partially widened, and the cogging force generated in this portion cancels the cogging force generated in the winding groove. Because
It is not necessary to provide a protruding portion in the radial direction on the surface of the armature opposed to the field, and it is possible to reduce the cogging force while preventing a reduction in effective magnetic flux and a reduction in efficiency. In addition, since the winding space can be widened, the winding is easy and the magnetic force of the armature can be increased. Since the peripheral surface of the armature facing the field can be formed in a circular shape without a protruding portion, the shape of the winding jig can be simplified.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a rotary electric machine according to the present invention, FIG. 2 is a partial sectional front view of the same as above, and FIG. 3 is a development showing various modifications of an armature applicable to the above embodiment. FIGS. 4 to 6 are front views showing specific examples of various structures of the armature, FIG. 7 is a plan view showing another embodiment of the rotating electric machine according to the present invention, and FIG. 8 is the same development. FIG. 9 is a front view showing various modifications of the armature applicable to the above embodiment, FIG. 10 is a plan view showing an example of a conventional rotating electric machine, and FIG. 11 is an enlargement of a part of the above conventional example. It is a top view. 10,30 …… Field magnet, 15,31 …… Armor, 112,123,313 …… Winding groove, 111,122,312 …… Salient pole.

Claims (1)

[Claims] 1. A field magnet and an electric machine, comprising: a field magnetized to an even number of poles; and an armature arranged facing the field magnet and having a plurality of winding grooves and a plurality of salient poles. In a rotary electric machine that rotates one of the rotors with respect to the other, when the number of field poles is P, it is a portion of the salient pole facing the field and is 360 degrees with respect to the positions of the winding grooves. 360 ° / P with respect to the position deviated by ° / P or the position of each winding groove above
And a plurality of parts deviated by an integer multiple thereof are formed with protrusions projecting in the axial direction and having a predetermined width, and when comparing this part and other parts with the same width in the circumferential direction, the above-mentioned protrusions are A rotating electric machine characterized in that the salient pole surface area of the formed portion is larger than the salient pole surface area of other portions.