JP2008043120A - Permanent-magnet rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent-magnet rotating electric machine with cogging torque reduced and manufacture man-days will not increase, even if the number of magnetic poles P and the number of slots S are combined in any way. <P>SOLUTION: In the permanent-magnet rotating electric machine having 24 (P=m×n) magnetic poles in a rotor 10, 8 (m=8); magnetic materials 11 are arranged uniformly by leaving intervals, and the magnetic material 11 is magnetized in 3 poles (n=3). In the magnetic material 11, the magnetic flux density distribution becomes a shape that becomes close to a sine wave, since it is set that θ<SB>1</SB>=12°<360/24, when a magnetic angle of the magnet poles at both ends is set to be θ<SB>1</SB>, and θ<SB>2</SB>=15°≥θ<SB>1</SB>, when the magnetic angle of the magnetic poles, other than those at both ends, is set to θ<SB>2</SB>so that cogging torque is reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a permanent magnet type rotating electrical machine. In particular, it is suitable for application to a direct drive brushless motor.

  Direct drive brushless motors are required to have small size, large torque, low torque ripple, and low price. In order to maintain the direct drive quality, the need for low torque ripple is high.

  One factor causing torque ripple is slot harmonic, which is a problem in the motor structure, and this is known to cause pulsation depending on the combination of the magnetic pole and the slot.

As a conventional technique for realizing low torque ripple by reducing the slot harmonics, a skewed structure is known, and a method of twisting skew by one slot with a stator is often used.
On the other hand, as shown in Patent Documents 1 and 2, a permanent magnet is provided with an auxiliary magnetic pole having a high magnetic permeability between different poles of a field magnetic pole made of a permanent magnet, and the positions of the auxiliary magnetic poles are not evenly arranged. A rotating electric machine is known.
JP-A-6-38475 JP-A-8-251847

However, the method described above is often used for large machines and distributed winding motors, but direct drive motors with strong demands for small size often use a concentrated winding structure, making it difficult to apply a status queue. .
For this reason, there is a technology that shifts the arrangement of the rotor permanent magnets in the circumferential direction as it advances in the axial direction and causes a skew effect, but in order to apply this, it is necessary to divide the magnet into several divisions in the axial direction, This leads to an increase in manufacturing steps, that is, an increase in cost.

There is also a technique called skew magnetization, but the advantage of skew magnetization can be exploited in the case of a ring magnet with an integrated magnet, and the ring magnet dimensions that can be formed with the current technology are limited. Therefore, application to a direct drive motor is often difficult.
In such a situation, a technique of reducing torque ripple by changing the combination of the number of magnet poles P and the number of slots S is often used. For example, a combination of P: S = 8: 9 or P: S = 10: 9 Is often used.

  This structure achieves low torque ripple compared to P: S = 4: 3 and P: S = 2: 3, but the degree of freedom in electrical design is reduced due to the limitations of the combination, especially large torque with the same dimensions and physique The increase in the number of poles aimed at making it impossible to deal with was limited by the number of slots.

  An object of the present invention is to provide a permanent magnet type rotating electrical machine that reduces the cogging torque and does not increase the number of manufacturing steps regardless of the combination of the number of magnet poles P and the number of slots S.

  The permanent magnet type rotating electrical machine according to claim 1 of the present invention that achieves the above object is a permanent magnet type rotating electrical machine having P (= m × n) magnetic poles in the rotor, wherein m (where m is 2 or more). (Even number) of magnet materials are arranged evenly spaced apart, and the magnet materials are magnetized to n poles (where n is an odd number of 3 or more).

A permanent magnet type rotating electrical machine according to a second aspect of the present invention that achieves the above-described object is the permanent magnet type rotating electrical machine according to the first aspect, wherein the magnet material has θ ₁ <360 ° when the magnetization angle of the magnetic poles at both ends is θ ₁ . / is P, when the magnetizing angle of the magnetic poles of the other two ends and theta _2, and θ ₂ ≧ θ _1, the angle of the magnet material intervals when the _{θ W, θ W = [360} ° - { 2θ ₁ + (n−2) θ ₂ } × m] / m.

The permanent magnet type rotating electrical machine according to claim 3 of the present invention that achieves the above object is a permanent magnet type rotating electrical machine having a P (= m × n) pole magnetic pole in the rotor, and has an angle θ ₂ of (n−2). ) M magnet groups (where m is an even number of 2 or more, where n is an odd number of 3 or more) and magnets having an angle θ ₁ are arranged at both ends of the magnet so that the polarities of adjacent magnetic poles are reversed. ) equally well as spaced apart a _{distance, θ 1 <360 ° / P} , and θ ₂ ≧ θ _1, the angle of the magnet group interval is taken as _{θ W, θ W = [360} ° - {2θ ₁ + (n−2) θ ₂ } × m] / m.

A permanent magnet type rotating electrical machine according to a fourth aspect of the present invention that achieves the above object is characterized in that, in the second or third aspect, when θ ₂ = 360 ° / P, 0.6 <θ ₁ / θ ₂ <0. 9 is a feature.
A permanent magnet type rotating electrical machine according to a fifth aspect of the present invention that achieves the above object is characterized in that, in the second, third or fourth aspect, when the angle of the magnet facing portion of the stator teeth is θ _teeth , θ ₁ <θ _teeth <characterized in that it was set to θ _2.

The direct drive brushless motor according to a sixth aspect of the present invention that achieves the above object is the direct drive brushless motor according to the first aspect, wherein the magnet material has a magnetization angle θ ₁ of the magnetic poles at both ends and a magnetization angle θ ₂ of the magnetic poles other than both ends. both, the _{θ P (= θ 1 = θ} 2), the angle of the magnet material intervals when the _{θ W, θ W = (360} ° -Pθ P) / m and the possible, in other words, 1 The non-polar range θ _W is uniformly positioned in the motor of the base, and a certain range of magnets is magnetized with multiple poles on one magnet material with the same magnetic pole angle θ _P (<360 ° / P). It is characterized by.

A permanent magnet type rotating electric machine according to claim 7 of the present invention to achieve the above problems is the permanent magnet type rotary electric machine having a magnetic pole of the P (= m × n) poles on the rotor, n pieces of angle theta _P (although n is an odd number equal to or greater than 3), and m magnet groups (where m is an even number equal to or greater than 2) are arranged evenly spaced apart from each other, and θ _P < It is characterized by being 360 ° / P.

  The permanent magnet type rotating electrical machine of the present invention has an effect of reducing the cogging torque by arranging a plurality of magnet materials or magnet groups evenly spaced apart so that the magnetic flux density distribution has a shape close to a sine wave.

    The form described as an example below is the best mode of the present invention.

  A direct drive brushless motor according to a first embodiment of the present invention is shown in FIG. The present embodiment relates to claim 1 or 2, and FIG. 1 shows a 24-pole outer rotor type motor.

  That is, in this embodiment, as an outer rotor type, eight (m = 8) magnet materials 11 are affixed to the inner surface of the outer rotor 10 at equal intervals, and one magnet material is provided. By magnetizing to 3 poles per contact (n = 3) (the boundaries of magnetization are shown by broken lines in the figure), a total of 24 poles (m × n = 8 × 3 = 24) are formed. .

Further, the stator 20 has 18 teeth 21 arranged uniformly. In the stator 20, concentrated windings (not shown) are provided as an integral core.
Therefore, since the number of poles P is 24 and the number of slots S is 18, the ratio of the number of poles P to the number of slots S is P: S = 24: 18 = 4: 3.

Here, with respect to the magnetization angle of one magnet material 11, the magnetization angle θ ₁ of both end poles is 12 °, and the magnetization angle θ ₂ of the central pole is 15 °. That is, θ ₁ <360 ° / 24 = 15 and θ ₂ ≧ θ ₁ .
Therefore, when the magnetization angle θ ₂ of the central pole and the magnetization angles θ ₁ and θ ₁ of both end poles are added, θ ₂ + 2θ ₁ = 15 ° + 2 × 12 ° = 39 °.

Therefore, the angle θ _W of the gap existing between the magnet material 11 and the magnet material 11 that are evenly arranged is θ _W = [360 ° − {2θ ₁ + (n−2) θ ₂ } × m] / m = [360 ° − {2 · 12 + (3−2) · 15} × 8] / 8 = (360 ° −39 × 8) / 8 = 6 °.
The ratio of the magnetization angle (θ ₁ / θ ₂ ) is important for reducing the cogging torque.
For example, the relationship between the magnetization angle θ ₁ of both end poles, the ratio of the magnetization angle (θ ₁ / θ ₂ ) and the cogging torque is shown in Table 1 and the graph of FIG. At this time, the magnetization angle θ ₂ of the central pole was set to a fixed value of 15 °.

As shown in FIG. 8, when the magnetization angle ratio (θ ₁ / θ ₂ ) decreases from 1 and falls below 0.9, the cogging torque decreases rapidly.
Further, when the ratio of magnetization angles (θ ₁ / θ ₂ ) is about 0.7 and the cogging torque takes the minimum value, and the ratio of magnetization angles (θ ₁ / θ ₂ ) is less than about 0.7, cogging is performed. It turns out that torque rises conversely.

Therefore, when the magnetization angle ratio (θ ₁ / θ ₂ ) is in the range of 0.9 to 0.6, a sufficient decrease in cogging torque is observed.
If the cogging torque is reduced to about 40%, the magnetization angle ratio (θ ₁ / θ ₂ ) is preferably in the range of 0.8 to 0.7.
If the cogging torque is to be reduced as much as possible, the magnetization angle ratio (θ ₁ / θ ₂ ) is preferably about 0.7.

As the magnetization angle ratio (θ ₁ / θ ₂ ) decreases from 1, the voltage gradually decreases. Therefore, if the cogging torque does not have a design problem, the voltage (torque) is set. In order to increase the ratio, it is desirable to increase the ratio of the magnetization angles (θ ₁ / θ ₂ ).
Therefore, in the example, θ ₁ / θ ₂ = 0.8.
Further, the angle θ _{teeth with} respect to the center of the magnet facing portion in the stator teeth 21 satisfies the following relational expression.
θ ₁ <θ _teeth <θ ₂

Since cogging torque increases when θ ₁ = θ _teeth and θ ₂ = θ _teeth , in this embodiment, θ _teeth is larger than 12 ° and smaller than 15 °, specifically, (12 + 15) / 2 = The angle was 13.5 °.
Although the present embodiment is an outer rotor type, the present invention is not limited to this, and an inner rotor type can be similarly configured.
In the above embodiment, the case of n = 3, that is, the case of magnetizing three poles per one magnet material, is not limited to this as long as n is an odd number of 3 or more. For example, when n is 5, when the magnetization angles of both end poles are θ ₁ , the magnetization angles of the central three poles are both θ ₂ .

A direct drive brushless motor according to a second embodiment of the present invention is shown in FIG. This embodiment relates to claim 3 and FIG. 2 shows a 24-pole outer rotor type motor.
In the first embodiment described above, eight magnet materials 11 magnetized to three poles are used, whereas in the present embodiment, eight magnet groups 12 including three magnets 12a, 12b, and 12a are used. The only difference is that the rest of the configuration is the same as that of the first embodiment.

That is, as an outer rotor type, eight magnet groups 12 are formed on the inner surface of the outer rotor 10 by arranging magnets 12a at opposite ends of one (n-2 = 1) magnet 12b so that the magnetic poles are reversed. (M = 8) Affixed evenly spaced to form a total of 24 poles (m × n = 8 × 3 = 24).
Here, the angle θ ₁ of the magnet 12a is 12 °, and the angle θ _{2 of the} magnet 12b is 15 °. That is, θ ₁ <360 ° / 24 = 15 and θ ₂ ≧ θ ₁ .

Therefore, in one magnet group 12, when the angle θ ₂ of the magnet 12b and the angles θ ₁ and θ ₁ of the magnet 12a are added, θ ₂ + 2θ ₁ = 15 ° + 2 × 12 ° = 39 °.
Accordingly, the angle θ _{W with} respect to the center of the gap existing between the magnet group 12 and the magnet group 12 that are evenly arranged is θ _W = [360 ° − {2θ ₁ + (n−2) θ ₂ } × m. ] / M = (360 ° −39 × 8) / 8 = 6 °.
As described above, the ratio (θ ₁ / θ ₂ ) of the angle θ ₁ of the magnets 12 a at both ends to the angle θ ₂ of the central magnet 12 b is important for reducing the cogging torque.

Further, the angle θ _{teeth with} respect to the center of the magnet facing portion in the stator teeth 21 satisfies the following relational expression.
θ ₁ <θ _teeth <θ ₂

A direct drive brushless motor according to a third embodiment of the present invention is shown in FIG. This embodiment relates to claim 6 and FIG. 3 shows a 24-pole outer rotor type motor.
In the first embodiment described above, the angle at which the magnet material 11 is magnetized is different between the central pole and the both end poles, whereas in this embodiment, the angle at which the magnet material 13 is magnetized is the center pole and both end poles. However, only the difference is the same, and the other configuration is the same as that of the first embodiment.

In other words, in this embodiment, as an outer rotor type, eight (m = 8) magnet materials 13 are affixed to the inner surface of the outer rotor 10 at equal intervals. By magnetizing 3 poles (n = 3) at equal intervals (in the figure, the boundaries of magnetization are indicated by broken lines), a total of 24 poles (m × n = 8 × 3 = 24) are formed. ing.
Here, the magnetization angle θ _P of each magnetic pole in each magnet material 13 is set to 13 °, which is smaller than 360 ° / P. That is, the angle of one magnet material 13 is 3 × 13 ° = 39 °.

Therefore, the angle θ _W of the gap that exists between the magnet material 13 and the magnet material 13 that are evenly arranged is θ _W = (360 ° −Pθ _P ) / m = (360 ° −24 × 13) / 8. = 6 °.
Corresponding to this magnetization angle θ _P , the angle θ _teeth of the magnet facing portion of the stator teeth 21 satisfies the following relationship.
θ _teeth = 3 × θ _P −720 / P = 3 × θ _P −720/24
However, θ _P <360 ° / P = 360 ° / 24

A direct drive brushless motor according to a fourth embodiment of the present invention is shown in FIG. This embodiment relates to claim 7, and FIG. 4 shows a 24-pole outer rotor type motor.
In the third embodiment described above, eight magnet materials 13 magnetized with three poles at equal intervals are used, whereas this embodiment is composed of three magnets 14a, 14a, 14a having the same size. The only difference is that eight magnet groups 14 are used, and the other configuration is the same as that of the third embodiment.

That is, as an outer rotor type, eight (m = 8) magnet groups 14 in which three (n = 3) magnets 14a are arranged on the inner surface of the outer rotor 10 so that the magnetic poles are reversed are evenly distributed. A total of 24 poles (m × n = 8 × 3 = 24) are formed.
Here, the angle θ _P of each magnet 14a is smaller than 360 ° / P and set to 13 °. That is, the angle of one magnet group 14 is 3 × 13 ° = 39 °.
Therefore, the angle θ _{W with} respect to the center of the gap existing between the magnet group 14 and the magnet group 14 that are evenly arranged is θ _W = (360 ° −Pθ _P ) / m = (360 ° −24 × 13). / 8 = 6 °.

Corresponding to the magnetic pole angle θ _P , the angle θ _teeth of the magnet facing portion of the stator teeth 21 satisfies the following relationship.
θ _teeth = 3 × θ _P −720 / P = 3 × θ _P −720/24
However, θ _P <360 ° / P = 360 ° / 24

[Contrast between the present invention and Patent Document 1]
The magnetic flux density distribution in the permanent magnet type rotating electrical machine of the present invention is schematically depicted in FIGS. 5 and 6 (repeated four times at a mechanical angle of 0 to 90 °). Since this is one cycle of electrical angle with one pole pair of 0-30 °, averaging the three pieces in the range of 0-90 ° gives the effect as if skewed, that is, the cogging torque. There is an effect to reduce.

That is, FIG. 5 shows a magnetic flux density distribution related to the first embodiment. In a permanent magnet type rotating electric machine having 24 poles (P = 24), the magnetization angle θ ₁ of both end poles is set to 12 ° (<360). ° / P), and the magnetization angle θ ₂ of the central pole was 15 ° (= 360 ° / P).

  Therefore, as shown in FIG. 5 (a), at a mechanical angle of 0 to 3 °, the magnetic flux density (represented by the ratio when the maximum value is 1 and the minimum value is −1, hereinafter the same) is 0, and the mechanical angle is 30. The magnetic flux density is 1 at ˜33 °, and the magnetic flux density is 1 at a mechanical angle of 60 to 63 °. When these are averaged, the magnetic flux density is 0 at an electrical angle of 0 to 36 ° as shown in FIG. (0 + 1 + 1) /3=0.66...

  Further, as shown in FIG. 5A, the magnetic flux density is 1 at a mechanical angle of 3 to 12 °, the magnetic flux density is 1 at a mechanical angle of 33 to 42 °, and the magnetic flux density is 1 at a mechanical angle of 63 to 72 °. When these are averaged, as shown in FIG. 5B, the magnetic flux density becomes (1 + 1 + 1) / 3 = 1 at the electrical angle of 36 to 144 °.

  Further, as shown in FIG. 5A, the magnetic flux density is 1 at a mechanical angle of 12 to 15 °, the magnetic flux density is 0 at a mechanical angle of 42 to 45 °, and the magnetic flux density is 1 at a mechanical angle of 72 to 75 °. When these are averaged, the magnetic flux density is (1 + 0 + 1) /3=0.66... At an electrical angle of 144 to 180 ° as shown in FIG.

That is, as shown in FIG. 5B, the magnetic flux density is 0.66 at an electrical angle of 0 to 36 °, the magnetic flux density is 1 at an electrical angle of 36 to 144 °, and the magnetic flux density is 0 at an electrical angle of 144 to 180 °. ..., It can be seen that the magnetic flux density distribution is line symmetric in the range of 90 ° front and back around the electrical angle of 90 °, and has a shape close to a sine wave.
Also, in the electrical angle of 180 ° to 360 ° shown in FIG. 5 (b), the sign is opposite to that described above, the line is symmetrical in the range of 90 ° front and back around the electrical angle of 270 °, and has a shape close to a sine wave. .

FIG. 6 shows the magnetic flux density distribution of the third embodiment. In a permanent magnet type rotating electrical machine having 24 poles (P = 24), all the magnetization angles θ _P are 13 ° (<360 ° / P).

  Therefore, as shown in FIG. 6A, the magnetic flux density is 0 at a mechanical angle of 0 to 1 °, the magnetic flux density is 1 at a mechanical angle of 30 to 31 °, and the magnetic flux density is -1 at a mechanical angle of 60 to 61 °. Therefore, when these are averaged, as shown in FIG. 6B, the magnetic flux density becomes (0 + 1−1) / 3 = 0 at the electrical angle of 0 to 12 °.

  Further, as shown in FIG. 6A, the magnetic flux density is 0 at a mechanical angle of 1 to 3 °, the magnetic flux density is 1 at a mechanical angle of 31 to 33 °, and the magnetic flux density is 1 at a mechanical angle of 61 to 63 °. When these are averaged, the magnetic flux density is (0 + 1 + 1) /3=0.66... At an electrical angle of 12 to 36 ° as shown in FIG.

  Further, as shown in FIG. 6A, the magnetic flux density is 1 at a mechanical angle of 3 to 12 °, the magnetic flux density is 1 at a mechanical angle of 33 to 42 °, and the magnetic flux density is 1 at a mechanical angle of 63 to 72 °. When these are averaged, as shown in FIG. 6B, the magnetic flux density is (1 + 1 + 1) / 3 = 1 at the electrical angle of 36 to 144 °.

  Further, as shown in FIG. 6A, the magnetic flux density is 1 at a mechanical angle of 12 to 14 °, the magnetic flux density is 0 at a mechanical angle of 42 to 44 °, and the magnetic flux density is 1 at a mechanical angle of 72 to 74 °. When these are averaged, the magnetic flux density is (0 + 1 + 1) /3=0.66... At an electrical angle of 144 to 168 ° as shown in FIG.

  Further, as shown in FIG. 6A, the magnetic flux density is 1 at a mechanical angle of 14 to 15 °, the magnetic flux density is 0 at a mechanical angle of 44 to 45 °, and the magnetic flux density is −1 at a mechanical angle of 74 to 75 °. Therefore, when these are averaged, as shown in FIG. 6B, the magnetic flux density is (1 + 0-1) / 3 = 0 at an electrical angle of 168 to 180 °.

That is, as shown in FIG. 6B, the magnetic flux density is 0 at an electrical angle of 0 to 12 °, the magnetic flux density is 0.66 at an electrical angle of 12 to 36 °, and the magnetic flux density is 1 at an electrical angle of 36 to 144 °. The magnetic flux density is 0.66 at an electrical angle of 144 to 168 °, and the magnetic flux density is 0 at an electrical angle of 168 to 180 °. It turns out that it becomes a shape close to a sine wave.
Also, in the electrical angle of 180 ° to 360 ° shown in FIG. 6 (b), the sign is opposite to the above, the line is symmetrical in the range of 90 ° front and rear around the electrical angle of 270 °, and has a shape close to a sine wave. .

Thus, in two examples (when θ ₁ <360 ° / P, θ ₂ = 360 ° / P and when θ _P <360 ° / P), the magnetic flux density distribution has an electrical angle of 90 ° ( 270 °), the shape is axisymmetrical in the range of 90 ° in the longitudinal direction, and has a shape close to a sine wave, so that an effect as if skewed, that is, an effect that cogging torque is reduced.

On the other hand, in the permanent magnet rotating electrical machine shown in FIG. 13 of Patent Document 1, it can be seen that the magnetic flux distribution is biased, as is apparent from the magnetic flux distribution shown in FIG.
That is, as shown in FIG. 7A, the magnetic flux density is 1 at a mechanical angle of 0 to 40 °, the magnetic flux density is 1 at a mechanical angle of 90 to 130 °, the magnetic flux density is 1 at a mechanical angle of 180 to 220 °, and the mechanical angle 270. Since the magnetic flux density is 1 at ˜310 °, when these are averaged, the magnetic flux density is (1 + 1 + 1 + 1) / 4 = 1 at an electrical angle of 0 to 160 °, as shown in FIG. 7B.

  7A, the magnetic flux density is -1 at a mechanical angle of 40 to 45 °, the magnetic flux density is 1 at a mechanical angle of 130 to 135 °, and the magnetic flux density is -1 at a mechanical angle of 220 to 225 °. Since the magnetic flux density is 1 at angles of 310 to 315 °, when these are averaged, the magnetic flux density is (1-1 + 1−1) / 4 at an electrical angle of 160 to 180 °, as shown in FIG. 7B. = 0.

That is, as shown in FIG. 7B, the magnetic flux density is 1 at an electrical angle of 0 to 160 °, and the magnetic flux density is 0 at an electrical angle of 160 to 180 °. Therefore, the magnetic flux density distribution is centered on an electrical angle of 90 °. It is not line symmetric in the range of 90 ° front and back. Therefore, it can be seen that the magnetic flux density distribution of the present invention has a shape closer to a sine wave.
Further, in the electrical angle of 180 ° to 360 ° shown in FIG. 7B, the sign is opposite to that described above, and the line is not line symmetric within the range of 90 ° front and back around the electrical angle of 270 °. Therefore, it can be seen that the magnetic flux density distribution of the present invention has a shape closer to a sine wave.

  As described above, Patent Document 1 discloses a technique in which the center of a magnetic pole is shifted to remove a harmonic of a specific order.

  In contrast, according to the present invention, by arranging a plurality of magnet materials or magnet groups evenly spaced from each other, the magnetic flux density distribution is line-symmetric in the range of 90 ° front and back around an electrical angle of 90 ° (270 °). That is, the arrangement is characterized in that a periodicity such as a skew appears so as to have a shape close to a sine wave.

  The present invention is suitable for application to a direct drive brushless motor, and is optimal, for example, for driving an automatic door directly through a pulley with a flat type and low speed torque.

1 is a configuration diagram of a direct drive brushless motor according to a first embodiment of the present invention. FIG. It is a block diagram of the direct drive brushless motor which concerns on 2nd Example of this invention. It is a block diagram of the direct drive brushless motor which concerns on the 3rd Example of this invention. It is a block diagram of the direct drive brushless motor which concerns on the 4th Example of this invention. FIG. 5A is a graph showing the relationship between the magnetic flux density and the mechanical angle in the first embodiment, and FIG. 5B is a graph showing the relationship between the magnetic flux density and the electrical angle in the first embodiment. FIG. 6A is a graph showing the relationship between magnetic flux density and mechanical angle in the third embodiment, and FIG. 6B is a graph showing the relationship between magnetic flux density and electrical angle in the third embodiment. FIG. 7A is a graph showing the relationship between the magnetic flux density and the mechanical angle in FIG. 13 of Patent Document 1, and FIG. 7B is a graph showing the relationship between the magnetic flux density and the electrical angle in FIG. is there. It is a graph which shows the relationship between ratio of magnetization angle ((theta) ₁ / (theta) ₂ ), voltage, and cogging torque.

Explanation of symbols

10 Outer rotor 11, 13 Magnet material 12, 14 Magnet group 12a, 12b, 14a Magnet 20 Stator 21 Teeth

Claims (7)

In a permanent magnet type rotating electric machine having P (= m × n) poles on a rotor, m magnet materials (where m is an even number of 2 or more) are evenly spaced apart and the magnet materials are A permanent magnet type rotating electrical machine characterized by being magnetized to n poles (where n is an odd number of 3 or more). The magnet material according to claim 1, wherein when the magnetization angle of the magnetic poles at both ends is θ ₁ , θ ₁ <360 ° / P, and when the magnetization angle of the magnetic poles other than both ends is θ ₂ , When θ ₂ ≧ θ ₁ and the angle of the magnet material interval is θ _W , θ _W = [360 ° − {2θ ₁ + (n−2) θ ₂ } × m] / m. A permanent magnet type rotating electrical machine. In a permanent magnet type rotating electrical machine having P (= m × n) poles on the rotor, an angle θ ₁ is provided at both ends of (n−2) magnets having an angle θ ₂ (where n is an odd number of 3 or more). M magnet groups in which magnets are arranged so that the polarity of adjacent magnetic poles are reversed (where m is an even number equal to or greater than 2) are evenly spaced and θ ₁ <360 ° / P, θ ₂ ≧ θ _1, and θ _W = [360 ° − {2θ ₁ + (n−2) θ ₂ } × m] / m, where θ _W is an interval angle between the magnet groups. Permanent magnet type rotating electrical machine. 4. The permanent magnet type rotating electrical machine according to claim 2, wherein 0.6 <θ ₁ / θ ₂ <0.9 when θ ₂ = 360 ° / P. _{5. The} permanent magnet type rotating electrical machine according to claim ₂ , wherein θ ₁ <θ _teeth <θ ₂ is satisfied when the angle of the magnet facing portion of the stator teeth is θ _teeth . 2. The magnet material according to claim 1, wherein both the magnetization angle θ ₁ of the magnetic poles at both ends and the magnetization angle θ ₂ of the magnetic poles other than both ends are θ _P (= θ ₁ = θ ₂ ). the angular spacing is taken as _{θ W, θ W = (360} ° -Pθ P) / m and then the permanent magnet type rotating electrical machine, characterized in that the. In a permanent magnet type rotating electrical machine having P (= m × n) poles in the rotor, the polarity of adjacent poles of n magnets of angle θ _P (where n is an odd number of 3 or more) is reversed. A permanent magnet type rotating electrical machine characterized in that m magnet groups (where m is an even number equal to or greater than 2) are arranged evenly spaced to satisfy θ _P <360 ° / P.

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