JP3426627B2 - Rotating electric machine and structure for reducing cogging force of rotating electric machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine and a rotary electric machine.
Field part with multiple magnetic poles related to the cogging force reduction structure
And the armature arranged coaxially with respect to the field part
Rotating electrical machine and cogging of the electrical machine
A structure for reducing force .

[0002]

2. Description of the Related Art Generally, a rotating electric machine such as a generator and a motor has a rotatable armature and N-pole and S-pole magnetic poles are alternately arranged on the outer periphery of the armature. And a field magnet section formed by The armature is radially provided with a plurality of teeth of a predetermined width protruding toward the outer circumference, and between the teeth is a slot for accommodating the armature winding. In addition, the width of the tip end of the tooth is often increased to form a salient pole portion. In such a rotary electric machine, a salient pole portion having a high magnetic permeability and an air gap corresponding to the slot are alternately arranged in the outermost peripheral portion of the armature facing the field portion along the rotation direction of the armature. Since they are arranged, they are not magnetically uniform.

An electromagnetic force generated in the field portion acts on the armature even when the armature winding is not energized.
Due to the magnetic nonuniformity, when the armature is rotated, the electromagnetic force acting on the armature changes according to the rotation angle of the armature. The electromagnetic force that changes due to the rotation of the armature is called cogging force, and when the armature winding is energized and the armature is actually rotated, it acts as unevenness of the rotating torque. A fan motor or the like is required to have less rotational torque unevenness, and a large cogging force adversely affects driving. Also, when the rotation of the armature is stopped, the magnetic nonuniformity makes it easier for the armature to stop at a predetermined rotation angle, and thus the positioning accuracy of the precision positioning motor or the like is reduced.

Conventionally, in order to reduce the cogging force,
An auxiliary groove is provided on the salient pole (see Japanese Patent Publication No. 58-42707).
It is proposed that a salient pole portion be provided with a convex portion (Japanese Patent Publication No. 2-19695). However, in all of these cases, the air gap between the field portion and the salient pole portion widens (the air gap spacing of the portion other than the convex portion also widens for the convex portion), so the effective magnetic flux decreases and the rotating electrical machine There is a problem that the efficiency of is reduced.

The present invention has been made in consideration of the above facts, and it is possible to obtain a rotating electric machine and a structure for reducing the cogging force of the rotating electric machine which can reduce the cogging force without lowering the efficiency. Is the purpose.

[0006]

In order to achieve the above object, a rotating electric machine according to the present invention comprises a field portion having a plurality of magnetic poles arranged along the circumferential direction, and a predetermined distance from the magnetic pole. An armature having a plurality of salient poles arranged so as to be opposed to each other at a distance and arranged coaxially with respect to the field unit, and the field unit and the armature are rotatable relative to each other. In an electric machine, when the least common multiple of the number p of magnetic poles of the field part and the number m of salient poles of the armature is G, an angle determined by the number and shape of salient poles is α, and a natural number is n, Central angle of salient pole θ
Is θ = (360 ÷ 2G × n) −α, where θ <360 ÷ m.

[0007] The angle α is determined in advance a predetermined value as the center angle θ of the salient pole, when the field portion and the armature are relatively rotated, the rotation of the salient pole of the central angle θ The force applied to one end along the direction is the first direction near the boundary of the magnetic poles.
The central angle of the salient pole when it peaks in the opposite direction, and the salient pole
The force applied to the other end along the rotation direction of the
Near the field, there is a peak in the second direction opposite to the first direction.
It can be obtained by measuring the difference between the central angle of the salient pole and the central angle of the salient pole .

Further , the cogging force of the rotating electric machine according to the present invention
The reduction structure includes a plurality of magnetic poles arranged in the circumferential direction.
The magnetic field portion provided is opposed to the magnetic pole at a predetermined distance.
With respect to the field portion includes a plurality of salient poles, which are sea urchin array good that
And an armature arranged coaxially with each other, and
A structure for reducing the cogging force of a rotating electric machine that can rotate relative to the armature.
And is applied to one end of the salient pole along the rotation direction.
Force is peaked in the first direction near the boundary of the magnetic poles.
And the other end of the salient pole along the rotation direction.
The second force, which is opposite to the first direction near the boundary of the magnetic poles.
When peaking in the direction of,
The central angle of the salient pole is different from the central angle of the magnetic pole.
Is characterized by.

[0009]

First, the analysis of the cogging force generated in the rotary electric machine by the inventors of the present application will be described by taking the rotary electric machine 10 shown in FIG. 1 as an example. The rotating electric machine 10 has six teeth 1 each having a predetermined width and radially protruding from the rotation center O of the rotating electric machine 10 toward the outer periphery at equal intervals (intervals of 60 °).
The armature 24 is formed with 2, 14, 16, 18, 20, and 22. The armature 24 is rotatable.

Further, the teeth 12 are extended at both ends on the tip side along the rotation direction of the armature 24, and the salient pole portion 2 is provided.
6A, the salient poles having a 2 6 B is formed. Due to the salient pole portions 26A and 26B, the salient pole 28 has a central angle of 45 °. In addition, other teeth 14, 16, 18, 2
0 and 22 have the same shape as the tooth 12,
Salient poles 30 and 3 each having a salient pole portion 26C to 26L at the tip thereof.
2, 34, 36 and 38 are formed.

On the other hand, a yoke 40 having a circular cross section is arranged on the outer circumference of the armature 24 so as to surround the armature 24, and either the N pole or the S pole is arranged on the inner circumference of the yoke 40. Eight magnetized magnetic poles 42A to 42H are arranged such that N poles and S poles are alternately arranged along the circumferential direction and a predetermined air gap is generated between the tip end of each tooth. ing. Each magnetic pole extends 45 ° along the circumferential direction of the center O.

Here, in a state where the armature 24 is stopped at the position shown in FIG.
Focusing on the vicinity of the stop position of the salient pole portion 26K of No. 2 (the area W shown in FIG. 1), the area W has the magnetic pole 4 as shown in FIG.
The salient pole portion 2 of the salient pole 20 from 2G through the air gap.
Magnetic flux (flow of magnetic flux is shown by magnetic force line 44 in FIG. 2) toward 6J and salient pole portion 26K of salient pole 22 is flowing. Figure 2
As shown in FIG. 5, the magnetic force lines 44 are curved, and Maxwell's magnetic stress is applied to each salient pole portion 26J, 26K in an attempt to straighten the curved magnetic force lines.

Therefore, a rotational force is applied to the salient pole portion 26J in the clockwise direction of FIG. 2 and a rotational force is applied to the salient pole portion 26K in the counterclockwise direction of FIG. This rotational force is the cogging force. The cogging force applied to each salient pole portion changes with the positional relationship between the salient pole portion and the magnetic pole, that is, with the rotation of the armature, and when the salient pole portion is located near the boundary between the magnetic poles, it goes to the salient pole portion. It is known that the number of lines of magnetic force decreases and a peak at which the change in cogging force is minimal (or maximal) occurs.

When the central angle of the salient poles and the central angle of the magnetic poles match (45 ° in FIG. 1) as in the rotating electric machine 10 shown in FIG. 1, the salient poles are projected along with the rotation of the armature 24. The edges at both ends of the pole correspond to the boundaries between the magnetic poles at the same timing. Therefore, conventionally, by matching the central angle of the salient poles with the central angle of the magnetic poles, the cogging forces applied to the salient pole portions at both ends of the salient poles have timings at which peaks in mutually different directions occur and cancel each other out. It has been considered that the cogging force applied to the salient pole can be reduced by the above.

However, the present inventors have found that the armature 24
The change in the number of magnetic force lines from the magnetic poles toward the salient poles and the change in the degree of bending are obtained in detail by simulation, and based on the results of the above simulation, both ends of the salient poles associated with the rotation of the armature 24 are detected. The change in applied cogging force was derived. As a result, even if the central angle of the salient poles is matched with the central angle of the magnetic poles, it has been found that the timings at which the cogging forces applied to the salient pole portions at the widthwise ends of the salient poles have different peaks in different directions are shifted. It was

FIG. 3 shows changes in the cogging force applied to the salient pole portions 26A and 26B of the salient pole 28 when the armature 24 of the rotary electric machine 10 in the state shown in FIG. 1 is rotated clockwise by 90 °. It is shown. As is apparent from FIG. 3, a predetermined cogging force for rotating the salient pole portion 26A in the counterclockwise direction is applied, and the edge portion of the salient pole portion 26A has magnetic poles 42H and 42H.
Position corresponding to the boundary A in the position rotated further than (the position shown in FIG. 1), the peak change in cogging force for rotating in the counterclockwise direction is minimum has occurred.

A cogging force for rotating the salient pole portion 26B in the clockwise direction is applied, and the magnitude of the cogging force is substantially equal to the cogging force applied to the salient pole portion 26A. However, in the salient pole portion 26B, the edge portions of the salient pole portion 26B have magnetic poles 42A and 42A.
Before reaching the position corresponding to the boundary of B, the clockwise direction
The peak at which the change in the cogging force is minimized is generated, and the peak at which the change in the cogging force is minimized is at salient pole portion 26A and salient pole portion 26B. There is an angle difference α. This resultant force is salient pole 2
It is the cogging force added to 8.

Due to the deviation of the peak position, the salient pole portion 26
The resultant force of the cogging force applied to A and the cogging force applied to the salient pole portion 26B is the position where the rotation angle is 45 ° as shown in FIG. 3, that is, the center of the salient pole and the center of the magnetic pole along the circumferential direction. before and after the matching position, resulting peaks of large amplitude a and a direction of rotating the different cogging force each direction acting cogging force around the rotating angle 45 ° is inverted.

The above is the case of paying attention to the salient pole portions 26A and 26B of the salient pole 28.
The cogging force is also applied to the salient pole portions 26C to 26L of 38.
Other salient poles 3 when the armature 24 is rotated as described above
The cogging force applied to the salient pole portions 26C to 26L of 0 to 38 changes as shown in FIGS. 4 (B) to 4 (F). Figure 4
Therefore, regarding the cogging force applied to the salient poles 30 to 38,
Rotation angle difference α (= 5 at salient poles at both ends along the circumferential direction)
Is generated, and the resultant force of these cogging forces greatly fluctuates with the rotation of the armature 24, as shown in FIG. This resultant force is the cogging force applied to the armature 24.

Based on the above facts, in the present invention, the least common multiple of the number p of magnetic poles in the field part and the number m of salient poles of the armature is G,
The angle determined by the number and shape of salient poles is α, and the natural number is n
And the central angle θ of the salient pole

[Equation 1] However, θ <360 ÷ m. The above formula (1) is an empirical formula found by the inventor. As an example, in the rotary electric machine 10 shown in FIG. 1, the number p of magnetic poles in the field magnet portion is 8 and the number m of salient poles of the armature is 6
Therefore, the least common multiple G becomes 24, and when the angle α = 5 ° is substituted into the equation (1) as described above, θ = 2.
5 °, 10 °, 12.5 °, 25 °, 32.5 °, 40
Solutions of 4 °, 47.5 °, 55 ° are obtained. Since the number of salient poles is 6, a value of 60 ° or more cannot be realized.
Therefore, the angle θ is limited to a value smaller than 360 ÷ m.

The operation of the present invention will be described below by taking the case where the central angle θ of the salient pole is 40 ° as an example. FIG. 5 shows a rotating electric machine 50 in which the central angle θ of the salient poles 28, 30, 32, 34, 36, 38 is 40 ° with respect to FIG. 1. Changes in the cogging force applied to the salient poles 28 to 38 when the armature 24 of the rotating electric machine 50 is rotated 90 ° clockwise from the state shown in FIG. 5 are shown in FIGS. 6 (A) to 6 (F). A change in the resultant force of the cogging force, that is, a change in the cogging force applied to the armature 24 is shown in FIG.

By setting the central angle θ to 40 °, as shown in FIG.
As shown in (1), due to the rotation of the armature 24, the cogging force applied to the salient pole portion 26A of the salient pole 28 and the cogging force applied to the salient pole portion 26B coincide with each other at the timing when peaks having different directions are generated, and the direction of the cogging force ( Since the direction of the rotational force is opposite, the peak of the cogging force is canceled. It should be noted that the method of changing the cogging force is not symmetrical with respect to the peak position in both the salient pole portion 26A and the salient pole portion 26B, so the cogging force cannot be completely canceled out, but the peak of the resultant force of the cogging force. The value is kept low.

As for the other salient poles 30 to 38, the salient pole portion 26C and the salient pole portion 26D of the salient pole 30, the salient pole portion 26E and the salient pole portion 26F of the salient pole 32, and the salient pole portion 34 are salient pole portions. 26G and salient pole portion 26H, salient pole portion 26I and salient pole portion 26J of salient pole 36,
In salient pole portion 26K and the salient pole portion 26L of the salient pole 38, the cogging force
The timings at which peaks having different directions from each other occur coincide with each other and are canceled in the same manner as described above. Therefore, as shown in FIG. 6 (G), as for the cogging force applied to the armature 24, the difference between the peak of the cogging force rotating in the clockwise direction and the peak of the cogging force rotating in the counterclockwise direction is conventionally (see FIG. G))
It can be suppressed to about 1/3.

As described above, according to the present invention, the cogging force can be reduced without providing a groove portion or a convex portion on the salient pole, so that it is more than necessary between the salient pole of the armature and the magnetic pole of the field portion. There is no need to provide an air gap, and the efficiency of the rotary electric machine does not decrease.

The cogging force of the rotating electric machine according to the present invention
The reduction structure is arranged in the rotation direction of the relative rotation between the field part and the armature.
The force applied to one end of the salient pole along the
Peak in any direction (eg clockwise or counterclockwise)
And the force applied to the other end of the salient pole along the rotation direction
In the vicinity of the boundary of the magnetic poles, it is possible to
The central angle of the salient pole so that
And the central angle of the magnetic pole are different, so the salient pole of the armature
Air gap more than necessary between the magnetic field and the magnetic pole of the field
The coggin of the rotating electric machine
It is possible to reduce the drag force.

[0026]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the section of the above action, the description has been given of the case where the central angle θ of the salient poles is set to 40 ° in the rotating electric machine having eight magnetic poles and six salient poles. In the electric machine, a case where another value derived from the equation (1) is applied as the central angle θ of the salient pole will be described as an example.

[First Embodiment] First, a first embodiment of the present invention will be described. As shown in FIG. 7, the rotary electric machine 56 according to the first embodiment radially projects from the rotation center O of the rotary electric machine 56 toward the outer periphery at regular intervals (60 ° intervals) in a predetermined width dimension. The armature 70 is provided with the teeth 58, 60, 62, 64, 66, 68 of the book. The armature 70 is rotatable. The space between the teeth is a slot, and accommodates an armature winding (not shown).

Both ends of the tooth 58 on the tip side are extended along the rotation direction of the armature 70, and the salient pole portion 7 is formed.
A salient pole having 2A and 72B is formed. The salient poles 72A and 72B make the central angle of the salient pole 74 55 °. In addition, other teeth 60, 62, 64, 6
6 and 68 have the same shape as the tooth 58,
Salient pole 7 having salient pole portions 72C to 72L at the tip end
6, 78, 80, 82, 84 are formed.

In the rotating electric machine 50 (see FIG. 5) described in the section of the operation, the cogging force is generated by matching the generation timings of the peaks of the cogging force applied to the two salient pole portions provided on the single salient pole. Although the present invention is configured to offset and reduce the offset, the present invention can offset the peak of the cogging force between the salient pole portions of different salient poles. Therefore, the rotary electric machine 56 of the first embodiment
Then, as an example of canceling the peak of the cogging force between the salient pole portions of different salient poles, the central angle θ of each salient pole is set to 55 °.

On the other hand, a yoke 86 having a circular cross section is arranged on the outer circumference of the armature 70 so as to surround the armature 70, and either the N pole or the S pole is arranged on the inner circumference of the yoke 86. Eight magnetized magnetic poles 88A to 88H are arranged so that N poles and S poles are alternately arranged along the circumferential direction and a predetermined air gap is formed between the tip of each tooth. ing. The magnetic poles 88A to 88H are extended at 45 ° along the circumferential direction of the center O, like the magnetic poles of the rotary electric machines 10 and 50.

Changes in the cogging force applied to the salient poles 74 to 84 when the armature 70 of the rotating electric machine 56 is rotated clockwise by 90 ° from the state shown in FIG. 7 are shown in FIGS. 8 (G) shows changes in the cogging force (the resultant force of the cogging forces) applied to the armature 70.

As is apparent from FIG. 8, in the rotary electric machine 56, the cogging force generated between the salient pole portion 72A at one end of the salient pole 74 and the salient pole portion 72J at the other end of the salient pole 82 is generated. Since the timings at which the peaks occur coincide with each other and the direction of the cogging force (direction of the rotational force) is opposite, the peaks of the cogging force are offset. Also, for other salient poles,
A pair of salient pole portion 72B of salient pole 74 and salient pole portion 72E of salient pole 78, salient pole portion 72C of salient pole 76 and salient pole portion 72L of salient pole 84.
Pair, salient pole portion 72D of salient pole 76 and salient pole portion 72 of salient pole 80
G pair, salient pole portion 72F of salient pole 78 and salient pole portion 7 of salient pole 82
The 2I pair, the salient pole portion 72H of the salient pole 80, and the salient pole portion 72K of the salient pole 84 pair the peaks of the cogging force at the same timing to cancel the peaks of the cogging force.

Therefore, in the same manner as described above, that is, in FIG.
As shown in, when the armature 70 is rotated, the difference between the peak of the cogging force that rotates the armature 70 in the clockwise direction and the peak of the cogging force that rotates the armature 70 in the counterclockwise direction is It can be suppressed to about 1/3 of the conventional value.
Therefore, it is not necessary to provide a groove portion or a convex portion on the salient pole as in the conventional case, and the cogging force can be reduced without lowering the efficiency of the rotary electric machine 56.

Since the distance between the salient poles decreases as the central angle of the salient poles increases, the magnetic flux easily flows from the magnetic poles to the salient poles and the efficiency improves, but the central angle of the salient poles is the central angle of the magnetic poles. When the value exceeds a large value, the magnetic flux reaching the core of the armature decreases conversely and the efficiency decreases. This is because the magnetic flux that has reached the salient pole from the magnetic pole passes near the surface of the salient pole and escapes to the magnetic pole adjacent to the magnetic pole. Therefore, the central angle of the salient poles is preferably smaller than the central angle of the magnetic poles, and even when it is larger than the central angle of the magnetic poles, it is preferable that the difference between the central angles is not so large.

[Second Embodiment] Next, a second embodiment of the present invention will be described. The first
The same parts as those in the embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 9, a rotary electric machine 90 according to the second embodiment has salient poles 92, 96, 1 having a central angle θ = 40 °.
00 and salient poles 94, 98, 102 having a central angle θ = 55 °
, And the armature 104 configured by being alternately arranged.

The central angle θ of the salient pole described in the section of action is 4
Referring to FIG. 6 showing the cogging force generated when the armature 24 of the rotary electric machine 50 is set to 0 °, a pair of the salient pole 28 and the salient pole 34, and a salient pole when the armature 24 is rotated. The cogging force generated by the pair of 30 and the salient pole 36 and the pair of the salient pole 32 and the salient pole 38 are the same. This is apparent from the fact that the salient poles have the same shape, the salient poles forming the pair are different from each other by 180 ° with respect to the center of rotation, and the positional relationship with respect to the magnetic poles is the same.

The same applies to the rotary electric machine 56 having the salient poles with the central angle θ of 55 ° described in the first embodiment. The salient poles 74 and 80 are paired, and the salient poles 76 and 76 are salient. The pair of 82 and the pair of salient pole 78 and salient pole 84 have the same cogging force.

Therefore, considering the reduction of the cogging force, the structure in which the salient poles 28, 32, 36 of the rotary electric machine 50 and the salient poles 76, 80, 84 of the rotary electric machine 56 are combined, that is,
As described above, the salient pole with the central angle θ of 40 ° and the central angle θ
Armature 1 having a structure in which salient poles with 55 ° are alternately arranged
It is apparent that the rotating electric machine 90 equipped with 04 can also reduce the cogging force.

The armature 104 of this rotating electric machine 90 is shown in FIG.
10A to 10F show changes in the cogging force applied to the salient pole portions 72A to 72L of the salient poles when rotated clockwise by 90 ° from the state shown in FIG. The change in (resulting force of cogging force) is shown in FIG.

With the above structure, FIGS. 10 (A) to 10 (F)
As is more apparent, the cogging forces of the salient poles 92, 96 and 100 are canceled by the two salient pole portions formed on each of them. Further, regarding the salient poles 94, 98, 102, the salient pole portion 72C of the salient pole 94 and the salient pole portion 7 of the salient pole 102 are provided.
The cogging force is canceled by the pair of 2L, the salient pole portion 72D of the salient pole 94 and the salient pole portion 72G of the salient pole 98, the salient pole portion 72H of the salient pole 98 and the salient pole portion 72K of the salient pole 102, respectively. It

Further, from FIG. 10, at the rotation angle where the peak of the cogging force is generated in each salient pole portion, the peaks of the cogging force of the other salient pole portions do not overlap, and the cogging force of the cogging force is not overlapped. The rotation angles at which peaks occur are dispersed. Therefore, as shown in FIG.
The difference between the peak of the cogging force that rotates the armature 104 in the clockwise direction and the peak of the cogging force that rotates the armature 104 in the counterclockwise direction when the
It can be kept as low as 17.

As a result, it is not necessary to provide a groove or a protrusion on the salient pole as in the conventional case, and the cogging force can be reduced without lowering the efficiency of the rotary electric machine 90.
Thus, the present invention is not limited to making the central angle of each salient pole constant.

[Third Embodiment] Next, a third embodiment of the present invention will be described. The first
The same parts as those in the embodiment and the second embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 11, the rotating electric machine 108 according to the third embodiment is provided with an armature 110 having a total of 12 teeth formed in a protruding manner. The salient poles 112, 116, 12 having a central angle θ = 32.5 ° are attached to the tips of the teeth.
0, 124, 128, 132 and salient poles 114, 118, 122, 126, 130, 134 having a central angle θ = 2.5 °.
And salient poles are formed so that and are alternately arranged.

The rotating electrical machine 108 of the third embodiment is constructed based on the idea that the central angle of each salient pole does not have to be constant, as described in the second embodiment. Two
Similar to the embodiment, the cogging force applied to the armature 110 can be significantly reduced. By using the salient poles with the central angle θ = 2.5 ° as the complementary poles, the winding method of the armature winding can be made the same as that of the rotary electric machine having six salient poles.

In the above embodiment, the rotary electric machine in which the field magnet portion is arranged on the outer periphery of the armature has been described as an example, but the present invention is not limited to this, and the armature is provided on the outer periphery of the field magnet portion. It is also possible to apply to a rotary electric machine having a structure in which is arranged. Also, the number of magnetic poles and the number of salient poles are not limited to the numerical values described above.

[0048]

As described above, in the present invention, the least common multiple of the number p of magnetic poles of the field part and the number m of salient poles of the armature is G, the angle determined by the number and shape of salient poles is α, The central angle θ of the salient pole when the natural number is n is θ = (360 ÷ 2G × n) −α However, since θ <360 ÷ m, the cogging force can be reduced without lowering the efficiency. It is possible to obtain an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a rotating electric machine having eight magnetic poles, six salient poles, and a salient pole angle of 45 °.

FIG. 2 is a conceptual diagram showing a flow of magnetic flux in a region W of the rotary electric machine of FIG.

FIG. 3 is a diagram showing a change in cogging force applied to salient pole portions 26A and 26B when the armature of the rotary electric machine of FIG. 1 is rotated.

4 (A) to (F) are diagrams showing changes in the cogging force applied to each salient pole portion when the armature of the rotating electric machine of FIG. 1 is rotated, and (G) is applied to the armature. It is a diagram showing a change in cogging force.

FIG. 5 is a schematic cross-sectional view showing the structure of a rotating electric machine having eight magnetic poles, six salient poles, and a salient pole angle of 40 °.

6A to 6F are diagrams showing changes in the cogging force applied to each salient pole portion when the armature of the rotating electric machine of FIG. 5 is rotated, and FIG. 6G is applied to the armature. It is a diagram showing a change in cogging force.

FIG. 7 is a schematic cross-sectional view showing the structure of a rotating electric machine having eight magnetic poles, six salient poles, and a salient pole angle of 55 ° according to the first embodiment.

8A to 8F are diagrams showing changes in the cogging force applied to each salient pole portion when the armature of the rotating electric machine of FIG. 7 is rotated, and FIG. 8G is applied to the armature. It is a diagram showing a change in cogging force.

FIG. 9 is a schematic cross-sectional view showing a structure of a rotating electric machine according to a second embodiment in which salient poles having an angle of 40 ° and salient poles having an angle of 55 ° with eight magnetic poles and six salient poles are combined.

10 (A) to (F) are diagrams showing changes in the cogging force applied to each salient pole portion when the armature of the rotating electric machine in FIG. 9 is rotated, and (G) is applied to the armature. It is a diagram showing a change in cogging force.

FIG. 11 is a schematic cross-sectional view showing a structure of a rotary electric machine according to a third embodiment, in which salient poles having 8 magnetic poles and 12 salient poles and having an angle of 32.5 ° and salient poles having an angle of 2.5 ° are combined. is there.

[Explanation of symbols]

10 rotating electric machines 24 Armature 26 salient pole 42 magnetic pole 50 rotating electric machine 56 rotating electric machine 70 Armature 72 salient pole 88 magnetic poles 90 rotating electric machine 108 rotating electric machine 110 armature

Continuation of the front page (56) Reference JP-A-2-84042 (JP, A) JP-A-61-240831 (JP, A) JP-A-61-92151 (JP, A) JP-A-61-102139 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 1/24

Claims (3)

(57) [Claims] 1. A field magnet portion having a plurality of magnetic poles arranged along a circumferential direction, and a field magnet portion having a plurality of salient poles arranged so as to face the magnetic poles at predetermined intervals. And an armature arranged coaxially with respect to the field armature, wherein the field part and the armature can rotate relative to each other, and the number of magnetic poles p of the field part and the armature G is the least common multiple of the number m of salient poles, and α is the angle determined by the number and shape of salient poles.
The central angle θ of the salient pole when the natural number is n, θ = (360 ÷ 2G × n) -α, where θ <360 ÷ m. Wherein said angle α is determined in advance a predetermined value as the center angle θ of the salient poles, when said field magnet part and the armature are relatively rotated, the salient poles of the central angle θ Force applied to one end of the
When peaks in the first direction near the boundary of the magnetic poles
Along the central angle of the salient pole of the
The force applied to the other end is near the boundary of the magnetic pole
Inside the salient pole when it peaks in the second direction opposite to the direction
The rotary electric machine according to claim 1 , wherein the difference is obtained by measuring a difference between the core angle and the core angle . 3. Multiple magnetic poles arranged along the circumference
Facing the magnetic field part with a certain distance from the magnetic pole
And a plurality of salient poles arranged so as to
And the coaxially arranged armature,
Cogging force reduction of rotating electric machine in which the armature and the armature can rotate relative to each other
Structure, The force applied to one end of the salient pole along the rotation direction is
When there is a peak in the first direction near the boundary of the magnetic pole,
The force applied to the other end of the salient pole along the rotation direction is the magnetic force.
In the second direction opposite to the first direction, the peak is generated near the boundary of the pole.
The center of the salient pole so that
Characterized in that the angle and the central angle of the magnetic pole are different.
A structure that reduces the cogging force of rotating electrical machines.