JP2007053864A - Permanent magnet embedded rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-output, low-loss efficient motor wherein leakage flux between magnetic poles is reduced and stress concentration due to centrifugal force is reduced and imbalance is suppressed during high-speed rotation. <P>SOLUTION: A permanent magnet embedded rotor 21 is constructed by: connecting two insertion holes 12, into which a permanent magnet 24 is inserted, are connected with each other through a gap 13 in each of rotor core pieces 11; thus forming the rotor core pieces so that a gap 13 is positioned on one side of every permanent magnet 24 and a coupling portion 14 is positioned on the other side; laminating the rotor core pieces so that the gaps and the coupling portions are alternated from one rotor core piece to another to form a rotor core 22; bonding permanent magnets 24 in the spaces 23 in the axial direction, formed by the insertion holes in the rotor core 22; and installing a rotating shaft 25 in the center hole 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a permanent magnet embedded motor that can realize high efficiency by using not only magnet torque but also reluctance torque by embedding a permanent magnet in a rotor.

  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 slit, and 34 is a rectangular hole 34. The rotor core 31 is generally provided with a slit 33 between the magnetic poles in order to reduce the leakage magnetic flux between the magnetic poles.

On the other hand, in order to reduce stress concentration due to centrifugal force in the thin part of the permanent magnet embedded rotor during high-speed rotation, a substantially arc-shaped slit is formed between the hole and the shaft hole that prevent leakage magnetic flux in the rotor core In addition, there has been proposed a technique in which the radial thickness between the inner periphery of the slit and the shaft hole is made equal to the radial thickness between the inner periphery of the rotor slot and the shaft hole (see, for example, Patent Document 1).
JP 2002-354726 A

  The problem to be solved is the generation of leakage magnetic flux between the magnetic poles inside the rotor core. In order to effectively use the magnet torque, it is ideal that the gap between the magnetic poles is reduced as much as possible and that there is no leakage magnetic flux, but if the gap between the magnetic poles is cut to reduce the leakage magnetic flux between the magnetic poles, the rotor core can be Are separated (divided) into a rotor core. In addition, when slits are provided between the magnetic poles, it is necessary to connect them at least so as not to be divided into the inside and the outside. Therefore, although the leakage magnetic flux is reduced, no further improvement in efficiency can be expected.

  On the other hand, there is a problem that stress concentration and unbalance occur due to centrifugal force during high-speed rotation.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, reduces leakage magnetic flux between magnetic poles, reduces stress concentration due to centrifugal force and suppresses unbalance during high-speed rotation, and has high output and high loss with high efficiency. The purpose is to provide.

  In order to solve the above problems, the present invention provides a rotor core in which two insertion holes for inserting permanent magnets are connected by a gap, and one side of all the permanent magnets is a gap and the other is a connection. And forming a rotor core by alternately laminating the gap portions and the connection portions for each of the rotor cores, and forming a permanent magnet in an axial space formed by the insertion hole portion of the rotor core. By fixing, the leakage magnetic flux between the magnetic poles can be reduced, and stress concentration due to centrifugal force can be reduced and unbalance can be suppressed during high-speed rotation.

  According to the embedded permanent magnet rotor of the present invention, all the permanent magnets have gap portions and connecting portions alternately in the axial direction, so that leakage magnetic flux can be reduced. Since the gap portions and the connection portions are alternately switched and stacked, reduction of stress concentration and unbalance due to centrifugal force can be suppressed during high-speed rotation.

  Further, the leakage magnetic flux can be further reduced by providing a slit in the connecting portion of the rotor core.

  In addition, the permanent magnet can be prevented from being positioned and displaced by eliminating the permanent magnet insertion hole only in the rotor core disposed on at least one outermost end surface.

  Moreover, cogging torque can be reduced by making the outer shape of the rotor core into a petal shape.

  Between the two insertion holes for inserting the permanent magnet is connected by a gap, and a rotor core is formed so that one side of all the permanent magnets is a gap and the other is a linkage, and a slit is provided in this linkage. The rotor cores are alternately laminated with the gap portions and the connection portions alternately stacked to form a rotor core, and permanent magnets are fixed to the axial space formed by the insertion holes of the rotor core. A permanent magnet embedded rotor is configured and arranged inside a cylindrical stator core around which a coil is wound.

  The permanent magnet embedded rotor according to the present invention will be described with reference to the drawings.

  FIG. 1 is an example of a plan view of a rotor core used in a permanent magnet embedded rotor according to the present invention. In FIG. 1, the rotor core 11 is formed so that two insertion holes 12 into which a permanent magnet is inserted are connected by a gap 13 so that one side of all the permanent magnets is a gap 13 and the other is a connecting portion 14. is doing.

  Further, the connecting portion 14 between the magnetic poles is provided with a slot 15 so as to reduce the leakage magnetic flux, and is configured to include the slit 15 when connecting the two insertion hole portions 12 with the gap portion 13. ing. Further, a central hole 16 is provided at the center of the rotor core 11, and the rotating shaft is mounted after the rotor is completed.

  Next, the embedded permanent magnet rotor of the present invention will be described with reference to the drawings. In FIG. 2, first, the rotor core 11 shown in FIG. 1 is laminated in the axial direction by alternately replacing the gap portions 13 and the connecting portions 14 for each one to form the rotor core 22.

  Permanent magnets 24 having different magnetic poles are alternately fixed to the space 23 in the axial direction of the rotor core 22 formed by the insertion hole 12 of the rotor core 11 with an adhesive, and finally the rotation shaft 25 is fixed to the central hole 16. The permanent magnet embedded rotor 21 is mounted.

  In this way, the rotor cores 11 are alternately stacked in the axial direction by alternately replacing the gap portions 13 and the connecting portions 14, and the permanent magnets 24 having different magnetic poles are disposed in the axial space portions 23 of the rotor core 22. The configuration is alternately fixed, and the conventional configuration can be applied to other configurations.

  With this configuration, the gap per magnetic pole increases, and the leakage magnetic flux can be reduced. Moreover, if a slit is provided in the magnetic pole coupling part, the leakage magnetic flux can be further reduced.

  At the same time, the gaps and connecting portions are alternately replaced one by one and laminated in the axial direction, so that the magnetic balance is stabilized and stress is not concentrated in one place from the viewpoint of mechanical strength. During high-speed rotation, stress concentration due to centrifugal force can be reduced and unbalance can be suppressed.

  Although not shown, a rotor core in which the permanent magnet insertion hole is eliminated on only one outermost end surface of the permanent magnet embedded rotor according to the first embodiment may be disposed, and the axial end surface of the permanent magnet is in contact with the rotor core. It is possible to easily regulate the position in the axial direction simply by fixing them.

  The interior permanent magnet motor (not shown) of the present invention is characterized by the configuration of the interior permanent magnet rotor, and is otherwise the same as the configuration of the conventional inner rotor type motor. The permanent magnet embedded rotor of the present invention may be disposed inside the cylindrical stator core around which the rotor is wound, and the rotating shaft may be supported rotatably.

  Thereby, leakage magnetic flux can be reduced and high output and high efficiency can be realized, and at the time of high speed rotation, stress concentration due to centrifugal force can be reduced and unbalance can be suppressed. Further, if the outer periphery of the rotor core is formed in a petal shape corresponding to each magnetic pole according to the pole tooth shape of the stator core and the permanent magnet, the cogging torque can be reduced.

  Therefore, the leakage magnetic flux between the magnetic poles of the permanent magnet embedded rotor can be reduced, and a high-efficiency motor with high output and low loss can be obtained. Further, during high-speed rotation, stress concentration can be reduced and unbalance can be suppressed, and a highly efficient embedded permanent magnet motor with low cost and low loss can be obtained.

  The embedded permanent magnet rotor and motor of the present invention are optimal for high output and high efficiency, and are useful for applications such as driving at high speed.

The top view of the rotor core in Example 1 of this invention Plan sectional drawing of the permanent magnet embedded type rotor in Example 1 of this invention Plan sectional view of a permanent magnet embedded rotor in a conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Rotor core 12 Insertion hole part 13 Cavity part 14 Connection part 15 Slot 16 Central hole part 21 Permanent-magnet embedded rotor 22 Rotor core 23 Space part 24 Permanent magnet 25 Rotating shaft

Claims (5)

In a permanent magnet embedded rotor in which permanent magnets are arranged so that magnetic poles are alternately different, a gap is connected between two insertion holes for inserting the permanent magnet, and one side of all the permanent magnets is a gap and the other The rotor core is formed such that the rotor core becomes a connecting portion, and the rotor core is formed by inserting the rotor core into the rotor core by alternately laminating the gap portion and the connecting portion for each sheet to form a rotor core. A permanent magnet embedded rotor having a permanent magnet fixed in an axial space. The embedded permanent magnet rotor according to claim 1, wherein a slit is provided in a connecting portion of the rotor core. The embedded permanent magnet rotor according to claim 1 or 2, wherein the permanent magnet insertion hole is eliminated only in the rotor core disposed on at least one outermost end surface. 4. The embedded permanent magnet rotor according to claim 1, wherein the outer periphery of the rotor core is formed in a petal shape corresponding to each magnetic pole to reduce cogging torque. 5. 5. A permanent magnet embedded motor in which the embedded permanent magnet rotor according to claim 1 is disposed inside a cylindrical stator core around which a coil is wound.

Images