JP2006074969A - Ac rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an AC rotating electric machine for reducing an iron loss, improving efficiency, and suppressing a torque fluctuation during rotation. <P>SOLUTION: In the AC rotating electric machine, a pair of rotor cores 3, 4 are provided with a plurality of pawl-shaped magnetic poles 2 and oppositely disposed, the rotor core 4 is magnetized as the S pole, the rotor core 3 is magnetized as the N pole, magnetic poles are formed by providing a permanent magnet 9 between the adjacent pawl-shaped magnetic poles 2, the permanent magnet 9 is disposed in the direction of polarity for strengthening magnetic fluxes generated in the pawl magnetic poles 2, and a portion of the generated magnetic flux has a component oriented in the radial direction of the rotor cores 3, 4. The magnetic saturation of the pawl-shaped magnetic pole 2 is prevented, and the iron loss is reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an AC rotating electrical machine used as an AC generator or an AC motor rotor, and more particularly to a technique for improving energy efficiency.

  As a conventional example of a rotating electrical machine, for example, one described in Japanese Patent Application Laid-Open No. 2003-324916 (Patent Document 1) is known. In Patent Document 1, two rotor cores having a plurality of claw-shaped magnetic poles are arranged to face each other, and a current is passed through a field winding provided inside the rotor core, whereby one rotor core is provided. Has been described. A technique for forming a Rundel type (sometimes referred to as a Landell type) rotating electrical machine is described.

Furthermore, a technique is disclosed in which a permanent magnet is disposed between claw-shaped magnetic poles adjacent to each other so as to have the same polarity, thereby increasing the magnetic flux. That is, the permanent magnet is arranged so that the claw-shaped magnetic pole side magnetized in the N pole is the N pole and the claw-shaped magnetic pole side magnetized in the S pole is the S pole, thereby strengthening the magnetic flux.
JP 2003-324916 A

  However, in the conventional example disclosed in Patent Document 1 described above, the claw-shaped magnetic pole has a projection shape that becomes narrower toward the tip, so that the magnetic flux passes through the tip of the claw-shaped magnetic pole. There is a problem that the area is reduced, magnetic saturation occurs, the iron loss is increased, and the efficiency is lowered.

  In addition, since the permanent magnet provided between the claw-shaped magnetic poles does not have a magnetic flux component in the radial direction of the Rundel-type iron core, in other words, the magnetic flux of the permanent magnet is only the circumferential component. There has been a problem that a sudden change in magnetic flux occurs at the connecting portion with the permanent magnet, causing torque fluctuations during rotation, causing noise and vibration.

  The present invention has been made to solve such a conventional problem. The object of the present invention is to reduce iron loss, improve efficiency, and suppress torque fluctuation during rotation. An object of the present invention is to provide an AC rotating electrical machine that can be used.

  In order to achieve the above object, according to the present invention, a pair of rotor cores each having a plurality of claw-shaped magnetic poles having a shape with protruding tip portions are arranged to face each other, and one of the pair of rotor cores is S. In an AC rotating electrical machine that forms a magnetic pole by magnetizing one pole, magnetizing the other to N pole, and providing a permanent magnet between the claw-shaped magnetic poles of each adjacent rotor core, the permanent magnet is: The polarity is arranged so as to increase the magnetic flux generated in the claw-shaped magnetic pole. Furthermore, at least a part of the generated magnetic flux has a component that faces the radial direction of the rotor core.

  In the AC rotating electrical machine according to the present invention, a permanent magnet disposed between a claw-shaped magnetic pole of a rotor core magnetized at the N pole and a claw-shaped magnetic pole of a rotor core magnetized at the S pole. However, since a magnetic flux is generated in the radial direction of each rotor core, the magnetic flux entering the claw-shaped magnetic pole from the permanent magnet is remarkably reduced, so that magnetic saturation of the claw-shaped magnetic flux can be prevented. Iron loss can be reduced. Thereby, efficiency can be improved.

  In addition, since the permanent magnet generates magnetic flux that faces the radial direction of the rotor core, it is possible to suppress rapid magnetic flux fluctuations between adjacent claw-shaped magnetic poles, and to generate noise and vibration due to torque fluctuations. Can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration of an AC rotating electrical machine according to the first embodiment of the present invention. As shown in the figure, this AC rotating electric machine 1 has a pair of rotor cores 3 and 4 each having a plurality of claw-shaped magnetic poles 2, and the claw-shaped magnetic poles 2 included in the respective rotor cores 3 and 4 have Oppositely arranged so as to engage with each other with a predetermined interval.

  FIG. 2 is a perspective view showing the configuration of the rotor cores 3 and 4. The rotor cores 3 and 4 are formed with a through hole 6 in the center and a center core 7 around the periphery. A field winding 8 (see FIG. 1) is wound around the center core 7.

  In addition, as shown in FIG. 1, the rotating shaft 5 is inserted into the through hole 6 in a state where the two rotor cores 3 and 4 are arranged to face each other, and the rotor core is interlocked with the rotating shaft 5. 3 and 4 rotate. Further, permanent magnets 9 each having a rectangular parallelepiped shape are disposed in the gaps between the claw-shaped magnetic poles 2 of the rotor cores 3 and 4.

  FIG. 3 shows a part of a cut surface obtained by cutting the AC rotating electrical machine 1 shown in FIG. 1 in a direction perpendicular to the rotating shaft 5 at the center. A claw-shaped magnetic pole 2 a shown in FIG. 2 is a claw-shaped magnetic pole provided on the rotor core 3 side, and is magnetized to the N pole when a direct current is passed through the field winding 8. The claw-shaped magnetic pole 2 b is a claw-shaped magnetic pole provided on the rotor core 4 side, and is magnetized to the S pole when a direct current is passed through the field winding 8.

  Each claw-shaped magnetic pole 2a, 2b is provided with an L-shaped groove 13 whose outer peripheral surface is slightly wider than the inner surface. By inserting the permanent magnet 9 into the L-shaped groove 13 portion, the permanent magnet 9 is rotated. The permanent magnet 9 is prevented from moving due to the centrifugal force acting on it.

  The permanent magnet 9 uses polar anisotropic magnets having an N pole and an S pole at each end of the same surface (rotor outer circumferential surface), and magnetizes the N pole as shown in FIG. The claw-shaped magnetic pole 2a side to be made is the N pole, and the claw-shaped magnetic pole 2b side magnetized to the S pole is the S pole.

  Next, the operation of the AC rotating electrical machine 1 according to this embodiment configured as described above will be described. When the AC rotating electrical machine 1 is operated, a DC current is passed through the field winding 8 wound around the center core 7 using a slip ring (not shown). Thereby, the rotor core 3 is magnetized to the N pole, and the rotor core 4 is magnetized to the S pole.

  Since the permanent magnet 9 uses polar anisotropic magnets having S and N poles on the same surface, the magnetic flux Φ from the S pole to the N pole is U-shaped as shown in FIG. It becomes a shape and has a component facing the radial direction of the rotor cores 3 and 4. For this reason, of the magnetic flux generated from the permanent magnet 9, the magnetic flux component entering the claw-shaped magnetic poles 2a and 2b is extremely reduced. As a result, the claw-shaped magnetic poles 2a and 2b can be prevented from being magnetically saturated, and loss caused by magnetic saturation, that is, iron loss can be reduced.

  FIG. 4 is a characteristic curve in which the horizontal axis indicates the distance in the outer peripheral direction of the AC rotating electric machine 1 and the vertical axis indicates the magnetic flux, and the portions indicated by x1, x2, and x3 are portions where the permanent magnet 9 is attached, y1 , Y2 and y3 are portions where the claw-shaped magnetic pole 2 exists. The claw-shaped magnetic pole 2a shown in FIG. 3 corresponds to the portion denoted by reference numeral y1, the claw-shaped magnetic pole 2b corresponds to the portion denoted by reference numeral y2, and the portion of the permanent magnet 9 corresponds to the portion denoted by reference numeral x2.

  As can be understood from the characteristic curve of FIG. 4, the permanent magnet 9 forms a magnetic flux in the radial direction of the rotor cores 3 and 4 (the radial direction of the AC rotating electrical machine 1). When moving from the claw-shaped magnetic pole 2a magnetized to the claw-shaped magnetic pole 2b magnetized to the S pole, the magnetic flux does not change abruptly but changes step by step. Therefore, it is possible to suppress the generation of noise and vibration due to a sudden torque fluctuation during rotation.

  Thus, in the AC rotating electrical machine 1 according to the present embodiment, as the permanent magnet 9 provided between the claw-shaped magnetic poles 2, polar anisotropic magnets having S and N poles on the same surface are used. Therefore, the magnetic flux component that the magnetic flux generated from the permanent magnet 9 enters the claw-shaped magnetic pole 2 can be reduced, and magnetic saturation can be prevented from occurring in the claw-shaped magnetic pole 2. Thereby, an iron loss can be reduced.

  Moreover, since a rapid change in magnetic flux between the claw-shaped magnetic poles 2 can be alleviated, a sudden change in torque can be suppressed, and noise and vibration can be prevented.

  Further, if the magnetic flux generated in the claw-shaped magnetic poles 2a and 2b and the magnetic flux generated by the permanent magnet 9 are set to have the same magnitude, as shown in FIG. It can also be set to switch between the poles. In FIG. 5, portions indicated by x11, x12, and x13 are portions where the permanent magnet 9 is present, y11 is a portion where the claw-shaped magnetic pole 2a is present, and y12 is a portion where the claw-shaped magnetic pole 2b is present.

  Further, in the above-described embodiment, the permanent magnet 9 has been described as an example using a rectangular parallelepiped shape, that is, a configuration in which a cross section in a plane perpendicular to the longitudinal direction is a rectangular shape, but various changes are made to the cross sectional shape. Thus, the magnetic flux can be changed more smoothly.

  For example, as shown in FIG. 6A, the cross section has a wave shape (a shape in which the center is recessed and both sides are convex in an arc shape), a V-shaped groove shape shown in FIG. 6B, or FIG. By using the arc groove shape shown, the magnetic flux distribution between the claw-shaped magnetic poles 2a and 2b can be set so as to change gradually and smoothly. With such a configuration, a magnetic flux distribution as shown in FIG. 7A can be obtained, and compared with the conventional case where FIG. 7B does not have a magnetic flux component facing the radial direction of the rotor core. Thus, the polarity of the magnetic flux can be changed smoothly. As a result, torque fluctuation can be suppressed, and noise and vibration can be prevented more effectively. In FIG. 7, portions indicated by x21, x22, and x23 are portions where the permanent magnet 9 is present, y21 is a portion where the claw-shaped magnetic pole 2a is present, and y22 is a portion where the claw-shaped magnetic pole 2b is present.

  Next, a second embodiment of the present invention will be described. FIG. 8 is an explanatory diagram showing the configuration of the second embodiment, and corresponds to FIG. 3 of the first embodiment described above. Moreover, the same code | symbol is attached | subjected to the same component.

  As shown in FIG. 8, in this embodiment, the permanent magnet 9 is comprised using the two plate-shaped magnets 11a and 11b. That is, the plate magnet 11a is provided on the claw-shaped magnetic pole 2a side magnetized to the N pole, and is arranged so that the N pole faces the outer peripheral side. Further, the plate-like magnet 11b is provided on the claw-shaped magnetic pole 2b side magnetized on the S pole, and is arranged so that the S pole faces the outer peripheral side.

  Therefore, the magnetic flux generated in the permanent magnet 9 composed of the two plate magnets 11a and 11b is the same as the direction from the S pole of the plate magnet 11b to the N pole of the plate magnet 11a, that is, the magnetic flux Φ shown in FIG. The magnetic flux entering the claw-shaped magnetic poles 2a and 2b from the permanent magnet 9 is extremely reduced. As a result, similarly to the first embodiment described above, the claw-shaped magnetic poles 2a and 2b can be prevented from being magnetically saturated. As a result, iron loss can be reduced, and noise and vibration can be prevented.

  Next, a third embodiment of the present invention will be described. FIG. 9 is an explanatory diagram showing the configuration of the third embodiment, and corresponds to FIGS. 3 and 8 described above. Moreover, the same code | symbol is attached | subjected to the same component.

  As shown in FIG. 9, in this embodiment, a yoke (magnetic path forming means) 12 is provided on the inner part of the permanent magnet 9 composed of the plate magnets 11a and 11b shown in FIG. And according to such composition, since the magnetic flux which permanent magnet 9 generates increases, more magnetic flux can be generated. Further, the magnetic strength of the plate magnets 11a and 11b used for generating the same magnetic flux can be reduced.

  This is extremely useful for improving the efficiency of a rotating electrical machine used for an AC motor or an AC generator.

1 is a perspective view showing a configuration of an AC rotating electrical machine according to an embodiment of the present invention. It is a perspective view which shows the structure of the rotor core of the alternating current rotating electrical machine which concerns on embodiment of this invention. It is sectional drawing of the nail | claw-shaped magnetic pole and permanent magnet which concern on the 1st Embodiment of this invention. It is a characteristic view which shows the magnetic flux change with respect to the circumferential direction distance of a rotor core. It is a characteristic view which shows the magnetic flux change with respect to the circumferential distance at the time of making the magnetic flux produced by a permanent magnet and the magnetic flux produced by a claw-shaped magnetic pole match. It is explanatory drawing which shows the cross-sectional shape of a permanent magnet. It is a characteristic diagram which shows the magnetic flux change with respect to the circumferential direction distance, (a) is a case where the magnetic flux between the claw-shaped magnetic poles is smoothly changed, (b) is a case where a permanent magnet having no magnetic flux component in the radial direction is used. Show. It is sectional drawing of the nail | claw-shaped magnetic pole and permanent magnet which concern on the 2nd Embodiment of this invention. It is sectional drawing of the nail | claw-shaped magnetic pole and permanent magnet which concern on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC rotary electric machine 2 Claw-shaped magnetic pole 3, 4 Rotor core 5 Rotating shaft 6 Through-hole 7 Center core 8 Field winding 9 Permanent magnet (Polar anisotropic magnet)
11a, 11b Plate magnet 12 Yoke (magnetic path forming means)
13 L-shaped groove

Claims (6)

A pair of rotor cores provided with a plurality of claw-shaped magnetic poles having protruding shapes at the tips are arranged opposite to each other, one of the pair of rotor cores is magnetized to the S pole, and the other is set to the N pole In an AC rotating electrical machine that forms magnetic poles by providing permanent magnets between the claw-shaped magnetic poles of the rotor cores that are magnetized and adjacent to each other,
The permanent magnet is arranged in such a direction that its polarity intensifies the magnetic flux generated in the claw-shaped magnetic pole, and at least a part of the generated magnetic flux has a component that faces the radial direction of the rotor core. Rotating electric machine.   The permanent magnet is a polar anisotropic magnet having S and N poles on the same surface, and the N pole is adjacent to the outer periphery of the claw-shaped magnetic pole of the rotor core magnetized to the N pole. The AC rotating electric machine according to claim 1, wherein the AC rotating electric machine is disposed so that an S pole is adjacent to an outer peripheral portion of the claw-shaped magnetic pole of a rotor core magnetized to the S pole.   The permanent magnet is composed of two plate magnets with one end being an S pole and the other end being an N pole, and the N pole of one of the plate magnets is a rotor core that is magnetized to the N pole. The S pole of the other plate-shaped magnet is disposed adjacent to the outer periphery of the claw-shaped magnetic pole, and is disposed adjacent to the outer periphery of the claw-shaped magnetic pole of the rotor core magnetized to the S pole. The AC rotating electric machine according to claim 1, wherein:   4. The AC rotation according to claim 3, further comprising magnetic path forming means for magnetically connecting the plate magnets to a surface of the plate magnets on the inner peripheral side of the claw-shaped magnetic poles. Electric.   3. The AC rotating electric machine according to claim 2, wherein the magnetic flux of the polar anisotropic permanent magnet is set so that the magnetic flux change between the claw-shaped protrusions adjacent to each other becomes smooth.   6. The AC rotating electric machine according to claim 5, wherein the polar anisotropic permanent magnet has a cross-sectional shape of any one of a wave shape, a V-shaped groove shape, and an arc groove shape.

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