JP2002204557A - Permanent magnet rotating electric machine having concentrated winding stator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve motor efficiency and reduce vibration, noise and wow/ flutters by moving a magnetic pole position detecting element in the direction of an opposition rotation in the range of 5 to 15 degrees of an electrical angle from an electrical neutral point in a permanent magnet type rotating electric machine of one directional rotation including a stator of a concentrated winding providing the ration of the number of magnetic poles M of the stator to the number of magnetic poles P of the permanent magnet of a rotor M:P equal to 6n: 6n±2 (n is an integer of 2 or larger) and also to solve disadvantages that a large peak is generated in a motor current waveform, motor efficiency is lowered, vibration, noise and wow/flutters become large in the permanent magnet type rotating electric machine including the stator of a concentrated winding in which the magnetic pole position detecting element is disposed at the electrically neutral point. SOLUTION: In the rotating electric machine including the stator of a concentrated winding in one directional rotation, the magnetic pole position detecting element is shifted in the opposite direction of rotation within the range of 5 to 15 degrees of the electrical angle from the electrically neutral point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet rotating electric machine, and more particularly, to a high efficiency, low wow and flutter, low vibration and low noise characteristic by reducing the magnitude of the armature current and the peak value of the armature current. An object of the present invention is to provide a permanent magnet rotating electric machine having the obtained concentrated winding stator.

[0002]

2. Description of the Related Art In the prior art, generally, in a permanent magnet rotating electric machine having a magnetic pole position detecting element, the magnetic pole position detecting element is electrically neutral in order to obtain the same rotation characteristics regardless of the rotation direction of the rotor. It was located at the point (zero degree in electrical angle).

Further, the number of M stator poles and the number of P permanent magnet poles are represented by M: P = 6n: 6n ± 2 (n is an integer of 2 or more).
For example, M: P = 12: 14 or M: P = 12:
In the case of the three-phase rotating electric machine of No. 10, the winding coefficient indicating the effective use of the winding is as large as 0.933, but general M: P = 12: 8.
With respect to the configuration described above, the mounting angle accuracy of the magnetic pole position detecting element is a mechanical angle, and the arrangement accuracy of 1.8 times for 14 poles and 1.25 times for 10 poles is required. (14/8 = 1.8, 10/8 =
1.25)

[0004]

In the prior art magnetic pole position detecting element having an electric neutral point arrangement, a large peak value is generated in the armature current waveform 52 as shown in FIG. The effective value of the current was large, the efficiency was low, the electromagnetic excitation force was large, and the vibration and the noise were large.

[0005] In addition, in contrast to a general configuration of M: P = 12: 8, the number of poles of the rotor is increased to 12:14 or 12: 1.
0, the mounting angle accuracy of the magnetic pole position detecting element is 1.8.
It is necessary to improve the mounting angle accuracy by a factor of 1.25 or 1.25, and there is a problem that the arrangement accuracy of the three magnetic pole position detecting elements varies during mass production, and motor characteristics, wow and flutter, vibration, and noise vary. Was.

SUMMARY OF THE INVENTION An object of the present invention is to provide a permanent magnet rotating electric machine having a concentrated winding stator which can solve the above-mentioned problems of the prior art. .

[0007] In the permanent magnet rotating electric machine having the concentrated winding stator according to the present invention, in order to solve the above-mentioned problem, the tips of M stator magnetic poles radially equally arranged on a substantially annular yoke. A permanent magnet having a pole piece projecting to the left and right, a stator having windings wound around the stator magnetic poles, and a P magnet pole rotatably held through the stator and a gap. In a unidirectional rotating permanent magnet rotating electric machine having a concentrated winding stator having a rotor provided with a magnetic pole position detecting element for detecting a magnetic pole position of a permanent magnet of the rotor, the magnetic pole position detecting element is electrically driven. A permanent magnet rotating electric machine having a concentrated winding stator was characterized in that it was arranged in an anti-rotation direction at an electrical angle of 5 to 15 degrees from the neutral point.

With this configuration, the armature current waveform becomes flat, the effective value current is small, the efficiency of the motor is improved, the imbalance of the electromagnetic exciting force is reduced, the efficiency is high, and the vibration is high. And noise is reduced.

According to a second aspect of the present invention, the number of stator poles and the number of P permanent magnet poles are M: P = 6n ± 2 (n Is 2
In the range of the angle of θ4 from the center line of the stator magnetic pole, the outer circumference of the pole piece protruding left and right at the tip of the stator magnetic pole has the same gap length with the permanent magnet as g1.
Thus, the range from θ4 to θ5 in the tip direction is formed such that the gap length g2 with the permanent magnet increases as it approaches the tip. With such a configuration, cogging torque is reduced, wow and flutter is reduced, and the effect of reducing rotation unevenness particularly at low speeds is great.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a plane including a shaft, showing a form of a three-phase permanent magnet rotating electric machine according to the present invention. In FIG. 1, an electric motor 1 includes a stator 2, a rotor 3, and a substrate 4. The stator 2 includes a stator core 5 and a three-phase concentratedly wound stator winding 6, and is attached to the cover 10. The rotor 3 has a holder 7 made of a cup-shaped magnetic material, and a ring-shaped,
A ferrite-based plastic permanent magnet 9 is arranged on the inner periphery of the holder 7. The holder 7 is fixed to a bush 19 made of aluminum or Shinchu material by fitting or caulking, and the bush 19 is pressed into the knurled portion 12 of the shaft 11. The substrate 4 is attached to the projection 17 of the cover 10 so as to face the axial end face 18 of the permanent magnet 9 on the cover 10. On the substrate 4, a magnetic pole position detecting element 13 for detecting the magnetic pole position of the permanent magnet 9, for example, a Hall element (three U, V, and W phases) is arranged. The rotor 3 is disposed between the rotor 3 and the cover 10 via a ball bearing 14, the axial thrust is adjusted by an ita spring 15, and the rotor 3 is fixed by a retaining ring 16.

FIG. 2 shows a permanent magnet 9 and a magnetic pole position detecting element 13 of the stator 2 and the rotor 3 of the permanent magnet rotating electric machine according to the present invention.
FIG. 4 is a radial cross-sectional view showing the positional relationship of FIG. The permanent magnet 9 of the rotor 3 is magnetized to 14 poles.

The stator 2 has twelve stator magnetic poles 20a to 20p radially arranged on the outer circumference of a substantially annular yoke 21 and protrudes left and right at the tip of the stator magnetic pole 20. The left and right pole pieces have the same size. FIG. 3 is an enlarged view of the shape of the pole piece 22. Pole piece 22
Has an arc shape in the range of an angle of θ4 right and left from the center line YY ′ of the stator magnetic pole 20, the gap length g1 with the permanent magnet 9 is uniform, and the angle of θ5 from θ4 toward both ends is In the range, the outer circumference of the pole piece 22 is formed such that the gap length g2 with the permanent magnet 9 increases toward the tip. As described above, by forming the outer periphery of the pole piece 22 so that the gap length in the portion from the angle θ4 to the angle θ5 increases, the magnetic flux distribution in the gap portion becomes gentle,
Since the cogging torque can be significantly reduced, the pulsation torque is reduced, and the rotational ruler at low speed is reduced. The stator winding 6 is intensively wound around each of the twelve stator poles 20. The magnetic pole position detecting element 13 has a mechanical angle 120
Three pieces are arranged on the substrate 4 at a pitch of degrees.

The stator shown in FIG. 2 constitutes a three-phase stator winding, in which the U phase is -U1 of 20a and + U1 and 20 of 20b.
+ U2 of g and -U2 of 20h are connected in series, and the V phase is + V1 of 20c, -V1 of 20d, -V2 of 20k, and 2
0m + V2 is connected in series, and the W phase is 20e + W1.
-W1 of 20f, -W2 of 20n, and + W2 of 20p are connected in series.

FIG. 4 is an exploded view showing the arrangement of the magnetic pole position detecting element 13. The position of the magnetic pole position detecting element 13 is set at a rotational direction N from the XX line which is a conventional electric neutral point. Are arranged on the line X′-X ′ shifted by θ degrees (electrical angle) in the anti-rotation direction.

In a conventional three-phase 120-degree permanent magnet rotating electric machine, since the magnetic pole position detecting element 13 is disposed at the electrical neutral point, θ1 is set to θ1 with respect to the induced voltage waveform 50 as shown in FIG. The armature current 51 is supplied so that 30 degrees, θ2 becomes 120 degrees, and θ3 becomes 30 degrees. However, if the position of the magnetic pole position detecting element 13 is displaced, a large peak value is generated as shown in a conduction waveform 52 as shown in FIG. 6, and the effective value of the conduction current is increased to lower the efficiency.

On the other hand, in the present invention, since the rotation direction is constant, as shown in FIG.
3 is arranged on the line X′-X ′, and θ1 is set to 20 degrees and θ is set to be 10 degrees earlier than the electric neutral point.
3 was set to 40 degrees. As a result, the deviation between the induced voltage and the conduction angle is reduced, and the conventional armature current waveform 52 shown in FIG. 6 has a peak current in the waveform, whereas the armature current of the present invention as shown in FIG. As shown by the waveform 53, the waveform is flat, has no distortion, and has almost no peak current, so that the effective value of the conduction current is reduced and the efficiency is increased.

FIG. 8 shows the relationship between θ and the efficiency η 54 when the position of the magnetic pole position detecting element 13 is shifted from the neutral line XX by θ degrees (electrical angle) as shown in FIG. The experimental data measured with the motor of the size is shown. When the electric neutral point θ = 0, the efficiency is η1, but when θ ranges from +5 degrees to +15 degrees in the advancing direction, the efficiency increases from η3 to η4. In particular, at +10 degrees, the maximum value is η2.

FIG. 9 shows the same motor and the magnetic pole position detecting element 13.
Shows the relationship of θ wow and flutter (W / F) 55 when the position is shifted from the neutral line XX by θ degrees (electric angle).
When the electric neutral point θ = 0 degrees, the value of the wow and flutter is WF1.
When the angle θ is in the advancing direction, that is, in the range of +5 degrees to 15 degrees, the value decreases from WF3 to WF4. Especially when θ = 10 degrees, W
F2 and the smallest.

According to the above experimental results, the magnetic pole position detecting element 1
The position 3 is preferably arranged at a position of 5 to 15 degrees in the anti-rotation direction from the position of the electrical neutral point, and the position of 10 degrees is determined to be optimal. In the embodiment, the pole piece 22 of the stator magnetic pole 20 has a uniform gap length g1 of 0.3 mm, an angle θ4 of about 8.37 degrees, and an angle θ5.
Is about 4 degrees, and the gap length g2 at the angle θ5 is 0.97 mm.

Further, in the present invention, even when the pole piece is not formed so as to change the length of the gap as shown in FIG. 3, the magnetic pole position detecting element is moved in the anti-rotation direction from the electrical neutral point. By arranging the magnetic pole position detection element in the range of 5 degrees to 15 degrees, the same effect can be obtained with respect to the improvement of the efficiency by the improvement of the conduction current waveform.
Similar effects can be obtained even when the arrangement is performed at a degree (mechanical angle) pitch.

Further, in the present invention, the case where M: P is 12:14 has been described, but the same effect can be obtained with 12:10.

Further, when M: P = 6n: 6n ± 2 (n is an integer of 2 or more), if the variation in the arrangement of the three magnetic pole position detecting elements is set in an electrical angle range of 5 to 15 degrees, Also, the efficiency, wow and flutter, noise, and the like can be reduced as compared with the case where they are arranged at an electrical neutral point.

[0023]

According to the present invention, there is provided a stator having a pole piece projecting left and right on M stator poles radially arranged on an annular yoke, and windings wound around the stator poles, and a gap between the stator and the air gap. And a concentrated winding stator having a magnetic pole position detecting element for detecting a magnetic pole position of a permanent magnet of the rotor. In the one-way rotating permanent magnet rotating electric machine having the magnetic pole position detecting element, the electrical angle from the electrical neutral point is 5 degrees to 1 degree.
Place 5 degrees in the anti-rotation direction. According to the above configuration, the motor current waveform becomes flat, the effective value current is reduced, the motor efficiency is improved, the imbalance of the electromagnetic excitation force is reduced, the efficiency is high, and vibration, noise, and wow and flutter are reduced. There is an effect that can be reduced.

[Brief description of the drawings]

FIG. 1 shows an axial sectional view of a permanent magnet rotating electric machine according to the present invention.

FIG. 2 is a radial sectional view of the permanent magnet rotating electric machine according to the present invention.

FIG. 3 shows an enlarged view of a stator magnetic pole of the present invention.

FIG. 4 is a developed view showing an arrangement of a stator magnetic pole, a permanent magnet of a rotor, and a magnetic pole position detecting element of the present invention.

FIG. 5 shows an induced voltage and a conduction current waveform of a conventional motor.

FIG. 6 shows a current waveform of a prior art motor.

FIG. 7 shows a current waveform of the motor of the present invention.

FIG. 8 is a diagram showing the relationship between the position of the magnetic pole position detecting element and the efficiency of the motor of the present invention.

FIG. 9 is a diagram showing the relationship between the position of a magnetic pole position detecting element and wow and flutter in the motor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Stator 3 Rotor 4 Substrate 5 Stator iron core 6 Stator winding 7 Holder 8 Air gap 9 Permanent magnet 10 Cover 11 Shaft 12 Knurl part 13 Magnetic pole position detecting element 14 Ball bearing 15 Ita spring 16 Stop ring 17 Cover Projection 18 Axial cross section of permanent magnet 19 Bush 20 Stator magnetic pole 21 Annular yoke 22 Pole piece 50 Induced voltage waveform 51 Armature current conduction range 52 Conventional armature current waveform 53 Armature current waveform of the present invention 54 Efficiency η 55 Wow and flutter W / F

Continued on the front page F term (reference) 5H019 AA03 AA06 BB05 BB15 BB20 BB22 CC04 DD01 EE14 5H621 AA02 AA04 BB07 GA01 GA04 GA15 HH05 JK02 JK14 5H622 AA02 CA01 CA05 CA10 CB05 PP05 PP19

Claims (2)

[Claims] 1. A stator according to claim 1, further comprising a pole piece protruding left and right at the tip of M stator poles radially arranged on a substantially annular yoke, and winding each of said stator poles. And a rotor having a permanent magnet having P magnetic poles rotatably held through an air gap with the stator, and a magnetic pole position for detecting a magnetic pole position of the permanent magnet of the rotor. In a unidirectional rotating permanent magnet rotating electric machine having a concentrated winding stator having a detecting element, the magnetic pole position detecting element is arranged in an anti-rotation direction in an electrical angle of 5 to 15 degrees from an electrical neutral point in electrical angle. Permanent magnet rotating electric machine having a concentrated winding stator. 2. The number of stator magnetic poles and the number of permanent magnet poles of P are configured such that M: P = 6n: 6n ± 2 (n is an integer of 2 or more). The outer periphery of the pole piece projecting right and left is within an angle range of θ4 from the center line of the stator magnetic pole, and the gap length with the permanent magnet is the same g1.
The range of θ5 from the tip to the tip is the gap length g2 with the permanent magnet.
2. The permanent magnet rotating electric machine having a concentrated winding stator according to claim 1, wherein the number of the windings increases as the distance from the tip increases.