JP3985281B2 - Rotating electric machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic pole structure of a rotating electrical machine such as an outer rotor type permanent magnet field brushless motor.
[0002]
[Prior art]
In general, among permanent magnet field brushless motors that are small and easy to increase output, an outer rotor type permanent magnet field brushless motor in which armature windings are concentrated and wound at one slot pitch (hereinafter abbreviated as concentrated winding), etc. The rotating electric machine of this type can shorten the coil end of the armature winding, and is more compact and advantageous for higher output.
[0003]
On the other hand, concentrated outer-rotor permanent magnet field brushless motors have a plurality of armature teeth provided on the outer periphery of the armature core of the fixed armature, so that the magnetic flux changes depending on the rotational position of the rotating field. This causes a problem that torque fluctuation (also referred to as torque ripple or cogging torque) tends to increase. Therefore, Japanese Patent Application Laid-Open No. 62-110468 discloses a technique that can reduce torque fluctuations without causing a decrease in output when the number of permanent magnet magnetic poles and the number of armature teeth are appropriately combined. Yes.
[0004]
In JP-A-62-110468, the number M of permanent magnet magnetic poles and the number of salient magnetic poles (number of armature teeth) N of a fixed armature are set to M = N−2 or M = N + 2. And N = 6n (n is an integer of 2 or more), the armature winding coefficient (an index representing how effectively the armature winding can use the magnetic flux of the magnetic pole) The content that the output can be improved is described.
[0005]
[Problems to be solved by the invention]
However, in the technique (conventional technique) described in Japanese Patent Application Laid-Open No. 62-110468, the number M of permanent magnet magnetic poles must be at least 10 or more from the relational expression of M and N. I understand. For this reason, in a brushless motor of a size that cannot integrally mold 10 or more permanent magnet magnetic poles, the number of parts of the permanent magnet magnetic poles is large, and the positioning and fixing method of the permanent magnet magnetic poles on the inner peripheral surface of the yoke is complicated. For this reason, the manufacturing workability at the time of manufacturing the magnetic pole part is poor, and the manufacturing cost of the magnetic pole part is increased. Therefore, it has been difficult to adopt the above structure for a relatively high output and inexpensive brushless motor.
[0006]
OBJECT OF THE INVENTION
The objective of this invention is providing the rotary electric machine which is small and is easy to make high output easily. It is another object of the present invention to provide a rotating electrical machine that can reduce the torque fluctuation of the magnetic pole part and reduce the manufacturing cost of the magnetic pole part.
[0007]
[Means for Solving the Problems]
According to the invention described in claim 1, without adding special members, by a part component which projects convexly into the inner diameter side of the part of the yoke and the soft magnetic material poles, permanent Since the amount of magnets used can be reduced, the manufacturing cost of the M pole part can be reduced. Further, by providing the protruding allowed part convexly to the inner diameter side of the part of the yoke, it is possible to increase the stiffness of the magnetic pole portion of the M electrode. In addition, when there is a margin in the magnetic flux density of the yoke, such as when using a ferrite magnet as a permanent magnet, it is possible to thin the yoke with a large light weight effect located on the outermost periphery of the magnetic pole part of the M pole. , Can achieve weight reduction.
Then, the first and second magnetized portions having different polarities are formed by the same magnetic pole member with the non-magnetized portion interposed therebetween, and adjacent to the soft magnetic material magnetic pole in which a part of the yoke protrudes convexly toward the inner diameter side. Therefore, the entire area of the soft magnetic material magnetic pole can be disposed on the side of the magnetic field increasing by the armature current, and the attraction torque can be effectively generated. Further, since the first magnetized portion of the permanent magnet magnetic pole is a permanent magnet, repulsive torque can be generated between the armature core of the fixed armature.
As described above, the usage amount of the permanent magnet can be reduced while maintaining the performance of the rotating electrical machine, and the manufacturing cost of the magnetic pole portion of the M pole can be suppressed. Furthermore, since the soft magnetic material magnetic pole is used as a positioning member that abuts the end face of the first magnetized portion of the permanent magnet magnetic pole, positioning becomes easy and the manufacturing process can be simplified.
[0008]
According to the second aspect of the present invention, the soft magnetic material magnetic pole is positioned so as to be positioned on the side of the magnetic field increasing by the armature current flowing through the armature winding from the center between the two permanent magnet magnetic poles adjacent to each other. By disposing the magnetic material magnetic pole, it is possible to effectively generate the attractive torque with the soft magnetic material magnetic pole by effectively utilizing the magnetomotive force due to the armature current, which is advantageous in terms of downsizing and higher output.
[0009]
According to the third aspect of the present invention, the magnetomotive force due to the armature current flowing through the armature winding is set by setting the polar arc ratio of the magnetic pole of the soft magnetic material within a suitable range of 0.3 to 0.6. Can effectively generate attraction torque with the magnetic pole of the soft magnetic material, which is further advantageous in terms of downsizing and higher output.
[0011]
According to the fourth aspect of the present invention, the magnetomotive force due to the armature current flowing through the armature winding is set by setting the polar arc rate of the soft magnetic material magnetic pole in a suitable range of 0.15 to 0.40. Since the suction torque can be effectively generated by effectively utilizing this, it is further advantageous in terms of small size and high output.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
[Configuration of the first embodiment]
1 and 2 show a first embodiment of the present invention, and FIG. 1 is a diagram showing the overall structure of an outer rotor type permanent magnet field brushless motor.
[0013]
An outer rotor type permanent magnet field brushless motor (hereinafter abbreviated as “brushless motor”) 1 includes a fixed armature (hereinafter referred to as an inner stator) 2 fixed to a fixing member (not shown), and a predetermined gap (outside of the inner stator 2). And a rotating field magnet (hereinafter referred to as an outer rotor magnetic pole) 3 which is disposed via an air gap (for example, 0.4 mm to 0.5 mm) and is rotatably supported with respect to the inner stator 2 by a bearing member (not shown). ing.
[0014]
The inner stator 2 includes an armature core (armature core) 4 that is a laminated core formed by laminating a large number of soft magnetic laminated materials (for example, iron plates or silicon steel plates), and a three-phase wound around the armature core 4. Armature coils (armature windings) 5A to 5L. Twelve armature teeth 4 </ b> A to 4 </ b> L having hook-shaped pieces protruding at the outer peripheral end are formed on the outer peripheral portion of the armature core 4 so as to protrude outward. A slot is formed between two adjacent armature teeth 4A and 4B.
[0015]
The three-phase armature coils 5 </ b> A to 5 </ b> L are armature windings of the present invention and are concentratedly wound around the N armature teeth 4 </ b> A to 4 </ b> L on the outer peripheral portion of the armature core 4. In addition, the number of armature teeth of the present embodiment is set so as to satisfy the following formula 1 (relational formula). In this embodiment, the number N of armature teeth is set to 12.
[Expression 1]
N = 6n (n is an integer of 2 or more)
[0016]
Here, the two sets of armature coils 5A and 5B are paired and connected with opposite polarities to form the same phase (U phase). The arrows FU1 and FU2 in FIG. 2 represent the armature magnetomotive force of the armature coils 5A and 5B in a certain energized state, and the arrow direction represents the N polarity. That is, the magnetomotive force in the gap of the armature coil 5A has a polarity on one side (S polarity), and the magnetomotive force in the gap of the armature coil 5B has a polarity on the other side (N polarity). ing.
[0017]
Further, two sets of armature coils 5G and 5H located 180 ° from the two sets of armature coils 5A and 5B are also paired and connected in opposite polarities to form the same phase (U phase). The armature coils 5A, 5B, 5G, and 5H forming the U phase are connected in series to form a U phase armature coil group.
[0018]
The other V and W phases are similarly connected. That is, the armature coils 5C, 5D, 5I, and 5J that form the V phase are connected in series to form a V phase armature coil group. The armature coils 5E, 5F, 5K, and 5L that form the W phase are connected in series to form a W phase armature coil group. And as a whole, U-phase, V-phase, and W-phase three-phase star connection or delta connection is used.
[0019]
The outer rotor magnetic pole 3 is a magnetic pole portion of the present invention and is mechanically coupled so as to transmit torque to an output shaft (not shown). The outer rotor magnetic pole 3 is a permanent magnet field composed of a rotor yoke 6 and permanent magnet magnetic poles 7A to 7E fixed to the inner peripheral surface of the rotor yoke 6 with an adhesive or the like. The permanent magnet magnetic poles 7A to 7E are made of a hard magnetic material (permanent magnet) that is strongly magnetized and holds magnetism permanently. In the present embodiment, for example, ferrite magnets are used as the permanent magnets constituting the permanent magnet magnetic poles 7A to 7E.
[0020]
The rotor yoke 6 is a substantially cylindrical yoke made of a soft magnetic material, and forms a part of a magnetic circuit and at the same time is a mechanical structure. Then, a part of the rotor yoke 6, that is, five locations every 72 ° in the circumferential direction of the rotor yoke 6 are soft magnetic material magnetic poles 6A to 6E made of a soft magnetic material. These soft magnetic material magnetic poles 6A to 6E are ridges formed by deforming a part of the rotor yoke 6 by, for example, press molding so as to protrude convexly toward the inner stator 2 (inner diameter) side. . The magnetic pole arc portions of the soft magnetic material magnetic poles 6A to 6E are, for example, 0.4 mm to 0.5 mm between the outer peripheral ends of the twelve armature teeth 4A to 4L, similarly to the magnetic pole arc portions of the permanent magnet magnetic poles 7A to 7E. The air gap is formed so as to face each other.
[0021]
As described above, the rotor yoke 6, the permanent magnet magnetic poles 7A to 7E, and the soft magnetic material magnetic poles 6A to 6E constitute the M-shaped outer rotor magnetic pole 3. Note that the number of magnetic poles of the outer rotor magnetic pole 3 is set so as to satisfy the following formula (relational formula), and in this embodiment, the number N of the armature teeth 4A to 4L is 12, so that M = 10 Is the pole.
[Expression 2]
M = N−2 or M = N + 2
[0022]
Next, the soft magnetic material magnetic poles 6A to 6E will be described in detail with reference to FIG.
The soft magnetic material magnetic pole 6A among the soft magnetic material magnetic poles 6A to 6E will be described as a representative. The soft magnetic material magnetic pole 6A has an increased magnetic field due to the armature current flowing through the armature coil by α1 (for example, 2 °) from the center (π / 5) between the two permanent magnet magnetic poles 7A and 7B adjacent at the center. It is arranged on the side (side attracted by the magnetomotive force generated in the armature coil).
[0023]
Further, assuming that the polar arc length of the soft magnetic material magnetic pole 6A is b1 and the magnetic pole pitch of the 10-pole outer rotor magnetic pole 3 is τ, the polar arc rate (b1 / τ) is in the range of 0.3 to 0.6 (the number In the embodiment, it is 0.44). The other soft magnetic material magnetic poles 6B to 6E have the same structure.
[0024]
[Operation of the first embodiment]
Next, the operation of the brushless motor 1 of this embodiment will be described with reference to FIGS.
[0025]
When the U-phase armature coil group and the V-phase armature coil group are energized, the magnetomotive force FU1 of the armature coil 5A acts in the attracting direction on the permanent magnet magnetic pole 7A, and a clockwise (clockwise) torque is generated. A clockwise torque acts on the rotor yoke 6. The magnetomotive force FU2 of the armature coil 5B acts on the soft magnetic material magnetic pole 6A in the attracting direction, and a clockwise torque is generated and acts on the rotor yoke 6. On the soft magnetic material magnetic pole 6A, the magnetomotive force FV1 of the armature coil 5C acts in the attracting direction, and a slightly counterclockwise torque is generated.
[0026]
However, in this embodiment, the center of the soft magnetic material magnetic pole 6A is positioned on the side of the magnetic field increasing by the armature current by α1 (for example, 2 °) from the center of the two permanent magnet magnetic poles 7A and 7B adjacent to each other. Since a part of the rotor yoke 6 is deformed into a convex shape toward the inner diameter side, the clockwise torque by the magnetomotive force FU2 of the armature coil 5B is dominant, and the counterclockwise torque by the magnetomotive force FV1 of the armature coil 5C is The size is negligible.
[0027]
Further, since the magnetomotive force FV1 of the armature coil 5C acts in the attracting direction and the magnetomotive force FV2 of the armature coil 5D acts in the repulsive direction, both of them generate a clockwise torque. Is generated, and a clockwise torque is added to the rotor yoke 6 to act.
[0028]
In FIG. 1, the directions of the total magnetomotive forces FU1 to FU4 of the currently energized U-phase armature coil group and the total magnetomotive forces FV1 to FV4 of the V-phase armature coil group are also indicated by arrows, and the outer rotor magnetic pole 3 and The operational relationship was shown. As can be seen from FIG. 1, clockwise torque is also generated in the lower half of the brushless motor 1, and the brushless motor 1 as a whole acts by adding clockwise torque to the rotor yoke 6.
[0029]
[Effects of the first embodiment]
As described above, according to the brushless motor 1 of the present embodiment, a soft magnetic material magnetic pole having an S polarity is formed without adding a special member by deforming a part of the rotor yoke 6 into a convex shape on the inner diameter side. Since 6A to 6E are used, the amount of permanent magnets used can be reduced by half. As a result, the assembling work for joining the permanent magnets to the inner peripheral surface of the rotor yoke 6 with an adhesive or the like is facilitated, and the number of permanent magnets can be halved, so that the manufacturing cost of the outer rotor magnetic pole 3 can be reduced.
[0030]
Further, according to the brushless motor 1 of this embodiment, the soft magnetic material magnetic poles 6 </ b> A to 6 </ b> E provided by deforming a part of the rotor yoke 6 constituting the outer rotor magnetic pole 3 into a convex shape reinforce the rotor yoke 6. By functioning as a rib, the rigidity of the outer rotor magnetic pole 3 can be increased. Further, when the magnetic flux density of the rotor yoke 6 has a margin (when a ferrite magnet is used as a permanent magnet), the rotor yoke 6 located at the outermost periphery of the outer rotor magnetic pole 3 and having a large light weight effect can be thinned. 1 can be reduced in weight. And there is also an effect that the moment of inertia of the outer rotor magnetic pole 3 can be reduced.
[0031]
Further, according to the brushless motor 1 of the present embodiment, since the rigidity of the outer rotor magnetic pole 3 is high, the vibration of the outer rotor magnetic pole 3 due to the attractive force and the repulsive force between the 12 armature coils 5A to 5L can be reduced. The brushless motor 1 with low vibration and low noise can be provided. Furthermore, according to the brushless motor 1 of the present embodiment, the number of magnetic poles of the soft magnetic material magnetic poles 6A to 6E is an odd five, but the armature teeth 4A to 4L that generate the armature magnetomotive force are different from those shown in FIG. As can be seen, the outer rotor magnetic poles 3 are opposed to each other at a position that is substantially symmetric with respect to the rotational axis, and the magnitude of the armature magnetomotive force is also symmetric with respect to the rotational axis, so that the force that decenters the outer rotor magnetic pole 3 can be reduced.
[0032]
[Configuration of Second Embodiment]
3 and 4 show a second embodiment of the present invention, and FIG. 3 is a diagram showing the overall structure of an outer rotor type permanent magnet field brushless motor.
[0033]
This embodiment is the same 10 pole 12 teeth (slot) brushless motor 1 as the first embodiment, but as shown in FIG. 3, the structure of the outer rotor magnetic pole 3 is different from that of the first embodiment. . In the outer rotor magnetic pole 3 of this embodiment, the polar arcs (circumferential length) of the soft magnetic material magnetic poles 6A to 6E formed by deforming a part of the rotor yoke 6 in a convex shape toward the inner diameter side are obtained from the first embodiment. Is also narrowing. As described above, the soft magnetic material magnetic poles 6A to 6E are different in the length of the magnetic pole arc from the first embodiment, but are functionally close members. Therefore, they are the same in order to correspond to the first embodiment. Numbers are given in the figure.
[0034]
The outer rotor magnetic pole 3 includes S-pole magnetized portions 9A to 9E adjacent to the soft magnetic material magnetic poles 6A to 6E and an N-pole magnetized portion 10A having the same function as the permanent magnet magnetic poles 7A to 7E of the first embodiment. 10E to 10E are integrated with the same magnet magnetic pole material (for example, resin or earthenware) with the non-magnetized portions 11A to 11E interposed therebetween, and permanent magnet magnetic poles 12A to 12E are provided.
[0035]
The S pole magnetized portions 9A to 9E are the first magnetized portions of the present invention, are made of a hard magnetic material, and are magnetized to S poles having the same polarity as the soft magnetic material magnetic poles 6A to 6E. The S-pole magnetized portions 9A to 9E constitute the S-pole magnetic pole arc (the magnetic pole arc remainder of the soft magnetic material magnetic poles 6A to 6E) together with the soft magnetic material magnetic poles 6A to 6E. The N-pole magnetized portions 10A to 10E are the second magnetized portions of the present invention, and are magnetic pole arcs of other magnetic poles magnetized to the N-pole having a different polarity from the soft magnetic material magnetic poles 6A to 6E. The non-magnetized portions 11 </ b> A to 11 </ b> E are portions that are not magnetized in either the N pole or the S pole, and are made of a magnetic pole material. The inner peripheral surfaces of these non-magnetized portions 11A to 11E are provided with recesses 11 provided to reduce useless magnet magnetic pole material.
[0036]
Next, the outer rotor magnetic pole 3 will be described with reference to FIG. 4 by taking one of the permanent magnet magnetic poles 12A to 12E as an example.
The permanent magnet magnetic pole 12B is an integral part magnetized with the non-magnetized portion 11A sandwiched between the S-pole magnetized portion 9B and the N-pole magnetized portion 10B, and is adjacent to or applied to the end of the soft magnetic material magnetic pole 6A. It is positioned in contact with each other, and is fixed to the inner peripheral surface of the rotor yoke 6 with an adhesive or the like.
[0037]
Further, as shown in FIG. 4, the magnetic pole arc of the S pole magnetized portion 9B is about half the length of the magnetic pole arc of the N pole magnetized portion 10B, and the magnetic flux on the demagnetization side due to the armature magnetomotive force. Is handled by the S-pole magnetized portion 9B. On the other hand, the soft magnetic material magnetic pole 6A is responsible for the magnetic flux on the magnetizing side due to the armature magnetomotive force.
[0038]
The soft magnetic material magnetic pole 6A has an armature current-enhanced magnetic field side (6 ° in this embodiment) from the center (π / 5) between the two permanent magnet magnetic poles 12A, 12B ( It is disposed on the side attracted by the armature magnetomotive force. Further, when the pole arc length of the soft magnetic material magnetic pole 6A is b2 and the magnetic pole pitch is τ, the polar arc rate (b2 / τ) of the soft magnetic material magnetic pole 6A is in the range of 0.15 to 0.40. (0.28 in this embodiment).
[0039]
The concave portion 11 on the inner peripheral surface of the non-magnetized portion 11B is a concave portion provided to reduce useless magnet magnetic pole material. However, even if the concave portion 11 is eliminated in consideration of the moldability of the permanent magnet magnetic pole 12B, performance is improved. There is no problem. Further, the non-magnetized portion 11B may have no magnetic charge on the air gap side, and a polar anisotropic magnetic path may be formed inside the non-magnetized portion 11B to increase the effective magnetic flux density. The permanent magnet magnetic poles 12A, 12C to 12E other than the permanent magnet magnetic pole 12B have the same structure.
[0040]
[Operation of the second embodiment]
Next, the operation of the brushless motor 1 of the present embodiment will be described with reference to FIGS. The description will be made with a single magnetic pole body focusing on the difference from the first embodiment.
[0041]
When the U-phase armature coil group and the V-phase armature coil group are energized, the magnetomotive force FU2 of the armature coil 5B acts on the soft magnetic material magnetic pole 6A in the attracting direction, generating clockwise torque. It acts on the rotor yoke 6. Since the length of the magnetic arcs of the soft magnetic material magnetic poles 6A to 6E is shorter than that of the first embodiment, no counterclockwise torque is generated as in the first embodiment due to the magnetomotive force FV1 of the armature coil 5C.
[0042]
For the permanent magnet magnetic pole 12B, the magnetomotive force FV1 of the armature coil 5C acts in a repulsive direction on the S pole magnetized portion 9B, and acts on the N pole magnetized portion 10B in the attracting direction. Further, the magnetomotive force FV2 of the armature coil 5D acts in the repulsive direction on the N-pole magnetized portion 10B, all generate clockwise torque, and the clockwise torque is added to the rotor yoke 6 to act.
[0043]
In FIG. 3, the directions of the total magnetomotive forces FU1 to FU4 of the U-phase armature coil group currently energized and the total magnetomotive forces FV1 to FV4 of the V-phase armature coil group are also indicated by arrows, and the outer rotor magnetic pole 3 and The operational relationship was shown. As can be seen from FIG. 3, a clockwise torque is generated also in the lower half of the brushless motor 1, and the brushless motor 1 as a whole acts by adding a clockwise torque to the rotor yoke 6.
[0044]
[Effect of the second embodiment]
According to the brushless motor 1 of the present embodiment, the S pole magnetized portions 9A to 9E and the N pole magnetized portions 10A to 10E are integrally formed by the same magnet magnetic pole member with the non-magnetized portions 11A to 11E interposed therebetween, and the rotor yoke 6 is adjacent to or brought into contact with the soft magnetic material magnetic poles 6A to 6E which are deformed so as to project partly toward the inner diameter side. Thereby, the soft magnetic material magnetic poles 6A to 6E can be disposed on the side of the magnetic field increasing by the armature current and can effectively generate the attraction torque.
[0045]
Moreover, since the magnetic pole arc remainders of the soft magnetic material magnetic poles 6A to 6E are configured by the S pole magnetized portions (permanent magnets) 9A to 9E, repulsive torque can be generated between the soft magnetic material magnetic poles 6A to 6E. Thus, the outer rotor magnetic pole 3 is configured so that the magnetic flux on the magnetizing side is handled by the soft magnetic material magnetic poles 6A to 6E and the magnetic flux on the demagnetizing side is handled by the S pole magnetized portions 9A to 9E. While maintaining the performance of the brushless motor 1 as compared to the embodiment, the number of parts of the permanent magnet can be reduced, and the manufacturing cost of the outer rotor magnetic pole 3 can be suppressed.
[0046]
Further, since the soft magnetic material magnetic poles 6A to 6E are used as positioning members for contacting the end surfaces of the permanent magnet magnetic poles 12A to 12E, the positioning of the permanent magnet magnetic poles 12A to 12E becomes very easy, and the manufacturing process of the outer rotor magnetic pole 3 is facilitated. It can be simplified. Furthermore, according to the brushless motor 1 of the present embodiment, the arc rate of the magnetic arcs of the soft magnetic material magnetic poles 6A to 6E is set to 0.15 to 0.40, which is suitable for torque generation. An attractive torque can be generated by effectively using the magnetomotive force generated by the child current, and the brushless motor 1 having a small size and high output can be manufactured.
[0047]
[Other Examples]
The case of the brushless motor 1 in which the number of magnetic poles of the outer rotor magnetic pole 3 is set to 10 and the number of armature teeth (slots) 4A to 4L is set to 12 has been described in the first and second embodiments. A combination example of the effective number of magnetic poles M and number N will be described below.
[0048]
The effective use of the magnetic flux of the outer rotor magnetic pole 3 (hereinafter abbreviated as “winding utilization factor”) should be originally examined by the product of the short winding coefficient and the distributed winding coefficient. It explains using only. When the short-pitch coefficient is kp, the following formula (relational expression) is established for the short-pitch coefficient kp, the number M of the outer rotor magnetic poles 3 and the number N of the armature teeth 4A to 4L.
[Equation 3]
kp = sin {(π / 2) × (M / N)}
[0049]
Based on the above relational expression, the short-pitch coefficient kp is good when the short-pitch coefficient kp is calculated in the range of the magnetic pole number M = 10-20 of the outer rotor magnetic pole 3 and the number of armature teeth N = 12-24. N (0.9 or more) is a combination of the following M and N.
However, the number of armature teeth was set only when the armature magnetomotive force was evenly balanced around the rotation center axis.
(M, N) = (10, 12), (14, 12), (16, 18), (20, 18), (20, 24), and kp ≧ 0.95 for all.
Moreover, although description is omitted, the winding utilization can be 0.93 or more in all combinations.
[0050]
From the above, when the combinations of M and N having good magnetic flux effective utilization rates are arranged, the number N and the number M of magnetic poles satisfying the following expression (relational expression) and expression 5 (relational expression) are desirable.
[Expression 4]
N = 6n (n is an integer of 2 or more)
[Equation 5]
M = N−2 or M = N + 2
[0051]
That is, when the relationship between the number N of the armature teeth and the number M of the outer rotor magnetic poles 3 is the above combination, the armature magnetomotive force can be used effectively, so that the output of the brushless motor 1 is not reduced and the outer rotor magnetic pole 3 is not caused. The torque fluctuation can be reduced, and the brushless motor 1 is advantageous in reducing the size and increasing the output. Since the number N of armature teeth is 6n (even), the armature magnetomotive force is balanced around the rotation center axis, and the armature magnetomotive force acts on the soft magnetic material magnetic poles 6A to 6E, so that the outer rotor magnetic pole 3 The force that decenters can be reduced.
[0052]
[Modification]
In this embodiment, a ferrite magnet is used as a permanent magnet. However, a rare earth magnet such as a neodymium magnet, an alnico magnet, or a resin magnet (a material obtained by sintering nylon resin, Nd, Fe, or B powder) may be used. Moreover, the number of magnetic poles of the permanent magnet magnetic pole and the soft magnetic material magnetic pole need not be the same, and a part of the permanent magnet magnetic pole in the above embodiment may be further replaced with a soft magnetic magnetic pole.
In the present embodiment, the present invention is applied to the outer rotor type permanent magnet field brushless motor, but the present invention may be applied to other electric motors and generators.
[0053]
As the rotor yoke 6, a substantially cylindrical shape obtained by press-molding a soft magnetic material (for example, pure iron, cast iron, mild steel plate, silicon steel plate, etc.) that is easy to be magnetized and demagnetized into a substantially cylindrical shape by seamless welding or the like. The yoke may be used. Further, as the rotor yoke 6, a cylindrical yoke in which a large number of substantially annular soft magnetic laminated materials (for example, iron plates or silicon steel plates) are laminated and connected may be used.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing the overall structure of a brushless motor (first embodiment).
FIG. 2 is a configuration diagram showing a main structure of a brushless motor (first embodiment).
FIG. 3 is a block diagram showing the overall structure of a brushless motor (second embodiment).
FIG. 4 is a configuration diagram showing a main structure of a brushless motor (second embodiment).
[Explanation of symbols]
1 Outer rotor type permanent magnet field brushless motor (rotary electric machine)
2 Inner stator (fixed armature)
3 Outer rotor magnetic pole (magnetic pole)
4 Armature core (armature core)
6 Rotor yoke
4A-4L Armature teeth 5A-5L Armature coil (armature winding)
6A to 6E Soft magnetic material magnetic poles 7A to 7E Permanent magnet magnetic poles

Claims (4)

An armature core having N armature teeth arranged on the outer periphery, a fixed armature having a three-phase armature winding wound around the N teeth at a pitch of 1 slot, and the fixing A magnetic pole portion of M poles arranged rotatably on the outside of the armature through a gap,
When the number of the armature teeth is N and the number of magnetic poles of the magnetic pole part is M,
N = 6n (n is an integer of 2 or more),
M = N−2 or M = N + 2
In rotating electrical machines that satisfy the relationship
Pole portion of said M pole, a yoke ing of a soft magnetic material,
A soft magnetic material magnetic pole formed by deforming a part of this yoke so as to protrude toward the armature core ;
Fixed permanent magnet poles on the inner peripheral surface of said yoke and <br/> Ri Tona,
The soft magnetic material magnetic pole is provided so that the center of the soft magnetic material magnetic pole is biased to the magnetic field increasing side due to the armature current,
The permanent magnet magnetic pole is adjacent to the soft magnetic material magnetic pole, and has a first magnetized portion having the same polarity as the soft magnetic material magnetic pole, a second magnetized portion having a different polarity from the first magnetized portion, and the A non-magnetized portion provided between the first magnetized portion and the second magnetized portion, the first magnetized portion and the second magnetized portion sandwiching the non-magnetized portion; A rotating electric machine characterized by being integrated with the same magnetic pole member . In the rotating electrical machine according to claim 1,
The soft magnetic material magnetic pole is provided such that the center of the soft magnetic material magnetic pole is positioned so as to be biased toward the side of increasing magnetic field by an armature current from the center between two adjacent permanent magnet magnetic poles. Rotating electric machine. In the rotating electrical machine according to claim 1 or 2,
A rotating electrical machine characterized in that a polar arc ratio of the soft magnetic material magnetic pole is in a range of 0.3 to 0.6. In the rotating electrical machine according to claim 1 ,
The rotating electrical machine according to claim 1, wherein a magnetic arc rate of the soft magnetic material magnetic pole is in a range of 0.15 to 0.40.

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