JP2007143331A - Permanent-magnet-embedded rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnet-embedded rotor and a motor with good controllability capable of reducing cogging torque and a torque ripple by effectively controlling leakage flux between magnetic poles in an inexpensive structure. <P>SOLUTION: This permanent-magnet-embedded rotor includes a rotor laminating rotor cores 11 having embedding slots 13 for placing permanent magnets 12 at equal intervals, and plate-shaped permanent magnets 12 inserted into the embedding slots 13. Magnet resistance enhancing sections 14 are formed in the centers of the embedding slots 13 on the outer circumferential side of the core. The permanent magnets 12 in which two poles are polarized in the almost outer circumferential direction have the same poles between adjacent embedding slots, and set the border of the magnetic poles in the centers of the magnet resistance enhancing sections 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic circuit configuration of a permanent magnet embedded rotor, and suppresses leakage magnetic flux generated between magnetic poles.

  A conventional permanent magnet embedded rotor will be described with reference to the drawings. In FIG. 3, 31 is a rotor core of an embedded magnet type motor, 32 is a permanent magnet inserted into the rotor core, 33 is a slot, and 34 is an embedded hole. In order to reduce the leakage magnetic flux between the magnetic poles, the rotor core 31 is generally provided with a slot 33 between the magnetic poles.

On the other hand, in order to respond to the increase in capacity, speed, performance (high responsiveness, high torque) and cost reduction of the motor, the yoke part that moves from the head constituting the magnetic pole of the rotor core to the cylindrical part Of the magnet embedded type in which two permanent magnets are arranged on the left and right sides of the yoke part, and two symmetrical long holes are formed in the head part. A permanent magnet synchronous motor type servo motor has been proposed (see, for example, Patent Document 1).
JP-A-11-252840

  The problem to be solved is the leakage magnetic flux generated between the magnetic poles of the permanent magnet embedded rotor. In order to effectively use the magnet torque, the gap between the magnetic poles must be reduced as much as possible, and there is no leakage magnetic flux. Ideal. However, if the gap between the magnetic poles is cut in order to reduce the leakage magnetic flux between the magnetic poles, the rotor core is separated (individed) into the inside and outside, and the rotor core is not established.

  On the other hand, the permanent magnet embedded type rotor has a problem in controllability due to a delay in follow-up of current due to reluctance torque. In addition, the cogging torque generated between the stator core and the stator iron core was larger than that of the SPM rotor provided with a permanent magnet on the rotor surface.

  Further, in the permanent magnet embedded rotor described in Patent Document 1, since it is necessary to divide the permanent magnet into two, man-hours for manufacturing the permanent magnet and mounting and fixing to the embedded hole are increased, resulting in an increase in cost.

  The present invention solves the above-described conventional problems, and provides a magnetically embedded rotor and motor that can effectively suppress leakage magnetic flux between magnetic poles with a low-cost configuration, have low cogging torque and reluctance torque, and good controllability. For the purpose.

  In order to solve the above-described problems, the present invention provides a rotor in which iron cores having embedded hole portions for arranging permanent magnets at equal intervals are laminated, and a flat permanent magnet inserted into each embedded hole portion of the rotor. A magnetic resistance increasing portion is formed at a central portion of the embedded hole portion on the outer peripheral side of the core, the permanent magnet is magnetized in two poles in a substantially outer peripheral direction, and the adjacent embedded hole portions have the same polarity and a magnetic pole By setting the boundary at the center of the magnetic resistance increasing portion, the leakage magnetic flux between the magnetic poles can be effectively suppressed with an inexpensive configuration.

According to the permanent magnet embedded rotor of the present invention, one permanent magnet is magnetized in two poles, and the magnetic resistance increasing portion is formed outside the magnetic pole boundary, so that the leakage magnetic flux can be effectively suppressed. Moreover, the leakage magnetic flux can be further reduced by making the magnetic resistance increasing portion into a slit.

  In addition, since the cogging torque and the reluctance torque can be suppressed as compared with the conventional one in which a single pole magnetized flat plate-like permanent magnet is disposed in one iron core head, controllability can be improved. .

  Furthermore, by combining a 10-pole magnet-embedded rotor and a stator having 12 salient cores with three-phase concentrated windings, leakage flux between magnetic poles can be suppressed with a low-cost configuration, and cogging torque and A permanent magnet embedded motor with small torque ripple and good controllability can be obtained.

  A rotor in which iron cores having embedded hole portions for arranging permanent magnets at equal intervals are laminated, and a plate-like permanent magnet inserted into each embedded hole portion of the rotor, on the outer peripheral side of the core of the embedded hole portion A magnetic resistance increasing portion is formed in the central portion, and the permanent magnet is magnetized in two poles in a substantially outer circumferential direction, the adjacent buried hole portions have the same polarity, and the magnetic pole boundary is set at the center of the magnetic resistance increasing portion.

  The permanent magnet embedded rotor according to the present invention is a magnetic circuit in which one permanent magnet to be installed in one embedded hole is magnetized in two poles and a magnetic resistance increasing portion is provided on the outer peripheral side of the core of the embedded hole. There is a characteristic in composition.

  Hereinafter, description will be given with reference to the drawings. In FIG. 1, 11 is a rotor core, 12 is a permanent magnet, 13 is a buried hole, 14 is a magnetic resistance increasing portion, and 15 is a rotating shaft.

  The rotor core 11 is provided with eight rectangular embedded hole portions 13 for accommodating the permanent magnets 2 at equal intervals, and a magnetic resistance increasing portion 14 is provided in the central portion on the outer peripheral side of the embedded hole portion 13 to laminate a predetermined quantity. is doing. Moreover, the iron core head between the adjacent magnetic resistance increasing portions 14 is set in a substantially arc shape.

  On the other hand, one permanent magnet 12 is magnetized in two poles with the center in the width direction as a boundary, and is attached to the embedded hole 13 so that the inside and outside between adjacent embedded holes 13 have the same polarity, and is fixed with an adhesive. . Thereafter, the rotary shaft 15 is mounted in the central hole of the rotor core 12 to form a permanent magnet embedded rotor.

  Thereby, since the magnetic pole boundary of the permanent magnet 12 magnetized with two poles coincides with the center of the magnetic resistance increasing portion 14, the leakage of magnetic flux between the magnetic poles can be suppressed.

  Moreover, it is not necessary to divide the permanent magnet for one pole like patent document 1, and it may be 8 pieces like the past, and can be comprised at low cost. Moreover, since the one end of the embedding hole is not open like patent document 1, mounting work can be performed easily.

  Further, since the permanent magnet for one pole is divided into two parts and bent in one iron core head, a plate-like permanent magnet with one pole magnetism is arranged in one iron core head as in the prior art. Compared to those, cogging torque and reluctance torque can be suppressed.

  The magnetic resistance increasing portion 4 of the first embodiment is set so as to be easily magnetically saturated by forming a thin portion formed by press working. Since the mechanical strength of the rotor core can be obtained, one permanent magnet is provided. It is suitable for large output (large diameter) motors that are subject to large centrifugal forces due to large high speed rotation.

On the other hand, the magnetic resistance increasing portion may be replaced with a thin portion and a slit connected to the outer periphery of the iron core, and leakage magnetic flux can be further suppressed. In this case, since the iron core head is held only between the embedded holes, care must be taken when the permanent magnet is mounted.

  In addition, since permanent magnets used for servo motors and the like are often sintered magnets and are easily cracked and chipped, small chamfers are provided at the corners. By chamfering or r riding the buried hole portions, the space between the buried hole portions is also reinforced and the iron core strength is improved.

  In addition, a rotor core without a permanent magnet insertion hole may be disposed only on one outermost end surface of the permanent magnet embedded rotor, and the axial end surface of the permanent magnet may be fixed only by contacting the axial end surface. Easy position regulation. Moreover, although it demonstrated with the 8-pole rotor, it is not limited to this. Furthermore, the petal shape of the rotor iron core is set by an arc or a smooth curve so that the permanent magnet is as close to the rotor outer periphery as possible.

  Example 2 is a permanent magnet embedded motor using the permanent magnet embedded rotor of the present invention.

  The permanent magnet embedded rotor of Example 2 includes 10 permanent magnets in all 10 embedded holes. The magnetic circuit configuration and effects are the same except that the magnetic resistance increasing portion in Example 1 is changed from a thin portion to a slit, and the number of embedded holes and permanent magnets is changed from eight to ten. The detailed explanation is omitted.

  Hereinafter, a permanent magnet buried type motor in which 12 salient cores are combined with a stator (12 slots) having three-phase concentrated windings will be described with reference to the drawings.

  In FIG. 2, 21 is a permanent magnet embedded rotor, and 22 is a stator. The stator 22 is formed by concentrating windings 24 around twelve salient cores 23 and combined with a 10-pole rotor. Therefore, the current direction of adjacent in-phase windings is opposite, and the current direction of adjacent different-phase windings is Are wound so that they are the same and are connected in a three-phase Y connection. Other than that, it is the same as the configuration of the conventional inner rotor type motor, and the permanent magnet embedded type rotor 21 may be disposed inside the stator 22 so as to rotatably support the rotating shaft.

  When the 8-pole rotor and the 12-slot stator are combined, the cogging torque generation order is 24, whereas in the motor of the second embodiment, the cogging torque generation order is significantly high as 60, and the cogging torque ripple is Reduce significantly.

  As in the first embodiment, the leakage magnetic flux can be suppressed while the permanent magnet is mounted in the embedded hole, and the cogging torque and the reluctance torque can be suppressed. For this reason, there is no worry about scattering of the permanent magnets in the high-speed rotation region, and the reliability is high and the output can be increased. In addition, in Example 2, since the cogging torque can be further suppressed, a permanent magnet embedded motor with better controllability is obtained.

  The embedded permanent magnet rotor and motor of the present invention are optimal for high speed and high output, and are useful for servo motors and the like where controllability is important.

Sectional drawing of the permanent magnet embedding type | mold rotor in Example 1 of this invention Sectional drawing of the principal part of the permanent magnet buried type motor in Example 2 of this invention Sectional view of permanent magnet embedded rotor in conventional example

Explanation of symbols

11 Rotor core 12 Permanent magnet 13 Buried hole 14 Magnetic resistance increasing part (thin part, slit)
15 Rotating shaft 21 Permanent magnet buried rotor 22 Stator 23 Salient pole iron core 24 Winding

Claims (3)

A rotor in which iron cores having embedded hole portions for arranging permanent magnets at equal intervals are laminated, and a plate-like permanent magnet inserted into each embedded hole portion of the rotor, on the outer peripheral side of the core of the embedded hole portion A magnetic resistance increasing portion is formed in the central portion, and the permanent magnet is magnetized in two poles in a substantially outer circumferential direction, the adjacent buried hole portions have the same polarity, and the magnetic pole boundary is set at the center of the magnetic resistance increasing portion. A permanent magnet embedded rotor. The permanent magnet embedded rotor according to claim 1, wherein the magnetic resistance increasing portion is a slit connected to the outer periphery of the rotor from the embedded hole. A permanent magnet in which 10 permanent magnets are provided in a total of 10 embedded holes, and a permanent magnet embedded rotor according to claim 1 and a stator having 12 salient cores and three-phase concentrated windings. Magnet buried type motor.

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