JP2013046508A - Claw-pole type motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a magnetic flux to be supplied to a stator by simplifying a structure.SOLUTION: An annular permanent magnet 40 magnetized in the rotating shaft direction is fitted and fixed to an annular cavity between a first claw-pole iron core 20 and a second claw-pole iron core 30. As a result, claw parts 22, 32 are used as an N-pole and an S-pole. Furthermore, a leakage magnetic flux is reduced by installing permanent magnets 50, 60 magnetized in the radial direction at the tip of the claw parts 22, 32.

Description

  The present invention relates to a claw pole type rotor, which is devised so that the structure can be simplified, the magnetic flux supplied to the stator can be increased, and high torque can be generated when assembled as a motor.

  Conventionally, there is an IPM (Interior Permanent Magnet) motor as a representative example of a high torque motor. The IPM motor is configured such that a permanent magnet mainly composed of a rare earth magnet is accommodated in the magnetic pole portion so that magnetic flux that generates reluctance torque and magnet torque in the rotor is passed through the magnetic pole.

  As a rotor of this type of motor, for example, as shown in FIG. 11 showing a quarter portion along the circumferential direction of the rotor structure, a rotor core 1 in which thin plates are laminated in an axial direction, and the rotor core 1 at a predetermined pitch. In the rotor of a permanent magnet type synchronous rotating electric machine comprising the provided rectangular permanent magnet insertion holes 2 and the permanent magnets 3 inserted into the permanent magnet insertion holes 2, the permanent magnet insertion holes 2 are provided every other pole pitch, and the radial direction A permanent magnet 3 having the same magnetic pole is inserted to constitute a rotor of a permanent magnet type synchronous rotating electric machine.

However, in the conventional motor, in order to generate a high torque in the rotor, a rare earth magnet is generally used as a permanent magnet, but there is a problem that the rare earth magnet is expensive.
Therefore, it is conceivable to replace it with an inexpensive ferrite magnet. However, a ferrite magnet with a small residual magnetic flux density cannot generate a sufficient torque, and the ferrite magnet has a small holding force. When the demagnetizing field is applied, the torque may be further reduced due to irreversible demagnetization.

  Moreover, as a rotor provided with a permanent magnet in the rotor, there are claw pole type rotors as shown in Patent Documents 1 and 2 below.

JP-A-11-341863 JP 2010-213455 A

Patent Document 1 shows a structure in which a DC field winding fixed to a bracket is built in a claw pole iron core via a gap.
However, this structure requires a DC power supply device in addition to the motor drive device, and there is a problem that the entire system becomes large. Further, there is a problem that a loss occurs in the DC field winding, resulting in a reduction in efficiency.

Patent Document 2 discloses a structure in which magnet torque and reluctance torque are used together by incorporating a permanent magnet for a field magnetized in the direction of the rotation axis in a claw pole iron core and a nonpolar claw pole iron core. Has been.
However, in this structure, in order to reduce the leakage flux of the permanent magnet magnetized in the direction of the rotation axis, it is necessary to keep the claw part of the claw pole iron core away from the permanent magnet in the radial direction, which increases the outer diameter of the rotor. is there. Further, if the outer diameter of the permanent magnet magnetized in the direction of the rotation axis is reduced in order to reduce the leakage magnetic flux of the permanent magnet magnetized in the direction of the rotation axis, there is a problem that the amount of magnetic flux is reduced and the magnet torque is reduced. .

  An object of the present invention is to provide a claw pole type rotor capable of increasing a magnetic flux supplied to a stator with a simple structure in view of the above-described conventional technology.

The configuration of the present invention for solving the above problems is as follows.
It has an annular shape in which a hole for insertion of the rotation shaft is formed at the center, is magnetized in the direction of the rotation axis, and one end surface becomes one of the N poles or S poles, and the other end surface has N A permanent magnet that is the other of the poles or the S poles;
An annular plate portion that comes into contact with the one end surface, and a plurality of claw portions that are arranged at a plurality of locations on the periphery of the annular plate portion and extend from the arrangement location along the rotation axis direction toward the other end surface. A first claw pole iron core provided;
An annular plate portion that contacts the other end surface, and is arranged at a plurality of locations on the periphery of the annular plate portion, extends from the arrangement location along the rotational axis direction toward the one end surface, and the circumferential position is A second claw pole core comprising a plurality of claws located between the claws of the first claw pole core;
It is arranged between each claw part of the first claw pole iron core and the peripheral surface of the annular plate part of the second claw pole iron core, and is magnetized in the radial direction so that the outer peripheral side has N or S poles. A permanent magnet which is one of the magnetic poles and whose inner peripheral side is the other magnetic pole of the N or S poles;
It is arranged between each claw part of the second claw pole iron core and the peripheral surface of the annular plate part of the first claw pole iron core, and is magnetized in the radial direction so that the outer peripheral side has N pole or S pole. A permanent magnet which is the other magnetic pole of which the inner peripheral side is one of the N or S poles;
It is characterized by having.

The configuration of the present invention is that the permanent magnets magnetized in the rotation axis direction and the permanent magnets magnetized in the radial direction are all ferrite magnets, or are all rare earth magnets,
Alternatively, the permanent magnet magnetized in the rotation axis direction is a ferrite magnet, and each permanent magnet magnetized in the radial direction is a rare earth magnet.

  Also, the configuration of the present invention is characterized in that any one of the above-mentioned claw pole type rotors is arranged in a plurality in the rotation axis direction.

  According to the present invention, the permanent magnets magnetized in the direction of the rotation axis can magnetize the claw portions of the first and second claw pole cores to the north and south poles, and are also magnetized in the direction of the rotation axis. Can have a large annular shape, so that a large amount of magnetic flux can be supplied to the stator.

  Moreover, by disposing a permanent magnet magnetized in the radial direction at the tip of the claw part of the claw pole iron core, the leakage magnetic flux is reduced, and the stator magnet is combined with the magnetic flux of the permanent magnet magnetized in the rotation axis direction. The amount of magnetic flux to be supplied can be further increased, and even when a ferrite magnet having a small residual magnetic flux density is used, a magnetic flux equivalent to that of a conventional rotating machine using a conventional rare earth magnet can be secured.

  Further, if a plurality of claw pole type rotors according to the present invention are arranged in the direction of the rotation axis and the surface area of the permanent magnet magnetized in the direction of the rotation axis is maximized, the amount of magnetic flux that can be supplied to the stator is maximized. be able to.

Further, in the claw pole type rotor of the present invention, if the permanent magnet magnetized in the rotation axis direction is composed of a ferrite magnet and the permanent magnet magnetized in the radial direction is composed of a rare earth magnet, the amount of rare earth magnets is the same as that of a conventional rare earth magnet. The IPM motor can be reduced by 40%, and a larger amount of magnetic flux can be supplied to the stator than the conventional IPM motor using rare earth magnets.
Furthermore, if the permanent magnet magnetized in the direction of the rotation axis is also a rare earth magnet, a higher torque claw pole motor can be realized.

  In addition, when an inexpensive bond-based magnet in which a rare earth magnet powder such as neodymium is mixed with resin is used as the permanent magnet, the magnet cost is reduced in the same manner as when the permanent magnet is a ferrite magnet. The cost of the pole type motor can be reduced.

The perspective view which shows the claw pole type | mold rotor which concerns on the Example of this invention. The disassembled perspective view which shows the claw pole type rotor which concerns on the Example of this invention. FIG. 3 (a) shows the state of leakage magnetic flux in the claw pole iron core, FIG. 3 (a) shows the state when there is no magnet magnetized in the radial direction, and FIG. 3 (b) shows the state when the magnet magnetized in the radial direction is provided. Figure. The block diagram which shows the composite claw pole type | mold rotor of the 2 step | paragraph structure based on the Example of this invention. FIG. 5A is a block diagram showing a first study / comparative example, FIG. 5A shows a two-stage composite claw pole rotor in which all permanent magnets are ferrite magnets, and FIG. The block diagram which shows the composite claw pole type | mold rotor of the 2 step | paragraph structure which eliminated the permanent magnet magnetized in the direction. The characteristic view which shows the magnetic flux density of the gap in a 1st examination and a comparative example. The block diagram which shows the composite claw pole type | mold rotor of the two-step structure which shows a 2nd examination and a comparative example. The characteristic view which shows the magnetic flux density of the gap in a 2nd examination and a comparative example. FIGS. 9A and 9B are configuration diagrams showing a third examination / comparative example. FIG. 9A shows a one-stage claw pole rotor, and FIG. 9B shows a two-stage composite claw pole rotor. Diagram. The characteristic view which shows the magnetic flux density of the gap in a 3rd examination and a comparative example. The block diagram which shows the conventional rotor of a permanent magnet type synchronous rotary electric machine.

  Hereinafter, embodiments of the present invention will be described in detail based on examples.

  FIG. 1 is a perspective view showing a claw pole type rotor 10 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof. 1 and 2, the direction of the rotation axis is indicated by a thin line arrow A. Moreover, in FIG. 2, the magnetization direction of each permanent magnet is shown by the thick line arrow.

  This claw pole type rotor 10 is an 8-pole rotor, and a field permanent magnet 40 is fitted into an annular cavity between the first claw pole iron core 20 and the second claw pole iron core 30. Fixed and configured.

  The permanent magnet 40 has an annular shape in which a hole 41 through which a rotation shaft (not shown) is inserted is formed at the center. The permanent magnet 40 is magnetized in the rotation axis direction, and one end face (for example, the upper ring-shaped end face in FIGS. 1 and 2) is an N-pole magnetic pole, and the other end face (for example, FIG. 1). 1, the lower ring-shaped end face in FIG. 2 is an S pole.

The first claw pole iron core 20 is integrally provided with an annular plate portion 21 and four claw portions 22.
The annular plate portion 21 has an annular shape in which a hole 21a through which a rotation shaft (not shown) is inserted at the center, and one end surface of the permanent magnet 40 (for example, the upper ring in FIGS. 1 and 2). Abutting end surface). The hole 21 a is formed at a position corresponding to the hole 41 of the permanent magnet 40.
The nail | claw part 22 is arrange | positioned at equal intervals at four places of the periphery of the annular plate part 21. FIG. The four claw portions 22 extend from the peripheral position of the annular plate portion 21 along the rotational axis direction from one end surface of the permanent magnet 40 toward the other end surface (downward). . In addition, the four claw portions 22 are positioned on the outer peripheral side with a gap from the outer peripheral surface of the permanent magnet 40.

The second claw pole iron core 30 is integrally provided with an annular plate portion 31 and four claw portions 32.
The annular plate portion 31 has an annular shape in which a hole 31a through which a rotation shaft (not shown) is inserted at the center, and the other end surface of the permanent magnet 40 (for example, the lower side in FIGS. 1 and 2). Ring-shaped end surface). The hole 31 a is formed at a position corresponding to the hole 41 of the permanent magnet 40.
The claw portions 32 are arranged at four equal intervals on the periphery of the annular plate portion 31. Each of the four claw portions 32 extends from the peripheral position of the annular plate portion 31 along the rotation axis direction from the other end surface of the permanent magnet 40 toward one end surface (upward). In addition, the four claw portions 32 are positioned on the outer peripheral side with a gap from the outer peripheral surface of the permanent magnet 40.

Regarding the circumferential position, the claw portion 32 of the second claw pole core 30 is located at a position between the claw portions 22 of the first claw pole iron core 20.
Further, with respect to the axial direction, the front end surface (lower end surface) of the claw portion 22 of the first claw pole iron core 20 extends to the position of the lower surface of the annular plate portion 31 of the second claw pole iron core 30; The front end surface (upper end surface) of the claw portion 32 of the second claw pole iron core 30 extends to the position of the upper surface of the annular plate portion 21 of the first claw pole iron core 20.

Between the inner peripheral surface of the front end portion (lower end portion) of the claw portion 22 of the first claw pole iron core 20 and the peripheral surface of the annular plate portion 31 of the second claw pole iron core 30, respectively, in the radial direction A permanent magnet 50 for preventing leakage magnetic flux magnetized in the magnetic field is disposed. In this example, each permanent magnet 50 has an N-pole magnetic pole on the outer peripheral side and an S-pole magnetic pole on the inner peripheral side.
Although details will be described later, the leakage magnetic flux can be reduced by arranging the permanent magnet 50.

Between the inner peripheral surface of the tip end portion (upper end portion) of the claw portion 32 of the second claw pole iron core 30 and the peripheral surface of the annular plate portion 21 of the first claw pole iron core 20, respectively, in the radial direction A permanent magnet 60 for preventing leakage magnetic flux magnetized in the magnetic field is disposed. In this example, each permanent magnet 60 has an S-pole magnetic pole on the outer peripheral side and an N-pole magnetic pole on the inner peripheral side.
Although details will be described later, the leakage magnetic flux can be reduced by arranging the permanent magnet 60.

In this embodiment, ferrite magnets can be employed as the permanent magnets 40, 50, 60.
Alternatively, the permanent magnet 40 may be a ferrite magnet, and the permanent magnets 50 and 60 may be rare earth magnets.
Further, the permanent magnets 40, 50, 60 can all be rare earth magnets.

  A claw pole type permanent magnet synchronous motor can be realized by incorporating the claw pole type rotor 10 having such a configuration into a stator around which a three-phase winding is wound.

  The claw pole type rotor 10 of the present embodiment magnetizes the claw portion 22 of the first claw pole iron core 20 to the N pole by the permanent magnet 40 magnetized in the rotation axis direction, and the claw of the second claw pole iron core 30. The portion 32 is magnetized to the south pole. Since the permanent magnet 40 magnetized in the direction of the rotation axis has a ring shape and can be made large in the radial direction, a large amount of magnetic flux can be supplied to the stator.

If only the permanent magnet 40 magnetized in the direction of the rotation axis is used as the permanent magnet and the permanent magnets 50 and 60 magnetized in the radial direction are not used, as shown in FIG. Leakage magnetic flux φl is generated at the tip of 20 claws 22 and the amount of magnetic flux supplied to the stator is reduced.
Similarly, leakage magnetic flux is also generated at the tip of the claw portion 32 of the claw pole iron core 30, and the amount of magnetic flux supplied to the stator is reduced.

Therefore, in this embodiment, as shown in FIG. 3 (b), the tip of the claw portion 22 of the claw pole rotor 10 is magnetized in the radial direction so that the outer peripheral side becomes the N pole and the inner peripheral side becomes the S pole. By disposing the permanent magnet 50, it is possible to reduce the leakage flux φl and further increase the amount of magnetic flux supplied to the stator together with the magnetic flux of the permanent magnet 40 magnetized in the direction of the rotation axis.
Similarly, at the tip of the claw portion 32 of the claw pole type rotor 10, a permanent magnet 60 that is magnetized in the radial direction and has an S pole on the outer peripheral side and an N pole on the inner peripheral side reduces the leakage magnetic flux. In addition, the amount of magnetic flux supplied to the stator can be further increased in combination with the magnetic flux of the permanent magnet 40 magnetized in the rotation axis direction.
That is, the permanent magnets 50 and 60 are magnetized in a direction that prevents the leakage flux φl of the permanent magnet 40.
As a result, even if a ferrite magnet having a small residual magnetic flux density is used as the permanent magnets 40, 50, 60, the amount of magnetic flux equivalent to that of the conventional rotating machine using the rare earth magnet of FIG. 11 can be secured.

Furthermore, if a plurality of claw pole type rotors 10 are arranged in the direction of the rotation axis and the surface area of the permanent magnets magnetized in the direction of the rotation axis is maximized, the amount of magnetic flux that can be supplied to the stator can be maximized. it can.
For example, FIG. 4 in which a ¼ portion along the circumferential direction of the rotor structure is particularly extracted shows a two-stage composite claw pole rotor in which two claw pole rotors 10 are arranged in the rotation axis direction. It is.

The conventional IPM motor using 8-pole 36-slot rare earth magnet and the stator are the same as the IPM motor. Magnetic field analysis is performed when the rotor is replaced with the claw pole rotor 10 of the present invention, and the magnetic flux density of the gap is examined. -A comparison was made.
Below, various examination and comparative examples are shown.

[Study / Comparative Example 1]
In the claw pole rotor 10 of the present invention, FIG. 5A shows a configuration when a ferrite magnet is used as the permanent magnet 40 magnetized in the rotation axis direction and the permanent magnets 50 and 60 magnetized in the radial direction. A comparison of the magnetic flux density in the gap is shown in FIG. In addition, the analysis when the permanent magnet magnetized in the radial direction was eliminated (FIG. 5B) was also performed. In FIGS. 5A and 5B, a symbol (f) is attached to the ferrite magnet portion.

The maximum magnetic flux density of the gap of the IPM motor using the conventional rare earth magnet is about 0.8T, whereas the claw pole rotor 10 of the present invention using the ferrite magnet is about 0.7T. The magnetic flux density substantially equivalent to that of an IPM motor using a conventional rare earth magnet can be obtained.
Further, when the permanent magnets 40 and 50 magnetized in the radial direction of the claw pole rotor of the present invention are eliminated (in the case of the configuration of FIG. 5B), the maximum value of the magnetic flux density of the gap is about 0.5T. Yes, the usefulness of the permanent magnet magnetized in the radial direction was confirmed.

[Study / Comparative Example 2]
In the claw pole rotor 10 of the present invention, FIG. 7 shows a configuration in which the permanent magnet 40 magnetized in the rotation axis direction is composed of a ferrite magnet and the permanent magnets 50 and 60 magnetized in the radial direction are composed of rare earth magnets. The magnetic flux density is shown in FIG. Note that the amount of rare earth magnets is reduced by 40% compared to the conventional IPM motor using rare earth magnets. In FIG. 7, the ferrite magnet portion is denoted by reference numeral (f), and the rare earth magnet portion is denoted by reference numeral (r).

In this example, the maximum value of the magnetic flux density of the gap is about 1.1 T, and the claw pole type rotor 10 of the present invention reduces the amount of rare earth magnets and has a larger magnetic flux density than an IPM motor using a conventional rare earth magnet. Can be obtained.
Furthermore, if the permanent magnet 40 magnetized in the direction of the rotation axis is also a rare earth magnet, a higher torque claw pole motor can be obtained.
Moreover, as a permanent magnet, it is good also as an inexpensive bond-type magnet which mixed the powder of rare earth magnets, such as neodymium, in resin. In this case, since the magnet cost is reduced as in the case where the permanent magnet is a ferrite magnet, the cost of the claw pole type motor can be reduced.

[Study / Comparative Example 3]
When the claw pole type rotor 10 of the present invention has a one-stage configuration in the rotation axis direction (FIG. 9A) and a two-stage configuration in the rotation axis direction (FIG. 9B), magnetic field analysis is performed. And compared the magnetic flux density of the gap. All permanent magnets were ferrite magnets. The magnetic flux density in the gap is shown in FIG. In FIGS. 9A and 9B, the ferrite magnet portion is denoted by reference numeral (f).

  As shown in FIG. 10, the maximum value of the magnetic flux density of the gap in the one-stage configuration is about 0.4 T, which is smaller than the two-stage configuration. This is because the surface area of the permanent magnet is larger in the two-stage configuration, and the amount of magnetic flux that can be supplied to the stator can be maximized by appropriately selecting the number of rotors arranged in the rotation axis direction according to the axial dimension of the motor. Recognize.

DESCRIPTION OF SYMBOLS 1 Rotor core 2 Permanent magnet insertion hole 3 Permanent magnet 10 Claw pole type rotor 20 1st claw pole iron core 21 Ring plate part 21a hole 22 Claw part 30 2nd claw pole iron core 31 Ring plate part 31a Hole 32 Claw part 40 Permanent magnet 41 hole 50,60 Permanent magnet

Claims (4)

It has an annular shape in which a hole for insertion of the rotation shaft is formed at the center, is magnetized in the direction of the rotation axis, and one end surface becomes one of the N poles or S poles, and the other end surface has N A permanent magnet that is the other of the poles or the S poles;
An annular plate portion that comes into contact with the one end surface, and a plurality of claw portions that are arranged at a plurality of locations on the periphery of the annular plate portion and extend from the arrangement location along the rotation axis direction toward the other end surface. A first claw pole iron core provided;
An annular plate portion that contacts the other end surface, and is arranged at a plurality of locations on the periphery of the annular plate portion, extends from the arrangement location along the rotational axis direction toward the one end surface, and the circumferential position is A second claw pole core comprising a plurality of claws located between the claws of the first claw pole core;
It is arranged between each claw part of the first claw pole iron core and the peripheral surface of the annular plate part of the second claw pole iron core, and is magnetized in the radial direction so that the outer peripheral side has N or S poles. A permanent magnet which is one of the magnetic poles and whose inner peripheral side is the other magnetic pole of the N or S poles;
It is arranged between each claw part of the second claw pole iron core and the peripheral surface of the annular plate part of the first claw pole iron core, and is magnetized in the radial direction so that the outer peripheral side has N pole or S pole. A permanent magnet which is the other magnetic pole of which the inner peripheral side is one of the N or S poles;
A claw pole rotor characterized by comprising: In claim 1,
The claw pole rotor characterized in that the permanent magnets magnetized in the direction of the rotation axis and the permanent magnets magnetized in the radial direction are all ferrite magnets or are all rare earth magnets. In claim 1,
The claw pole rotor characterized in that the permanent magnets magnetized in the direction of the rotation axis are ferrite magnets, and each permanent magnet magnetized in the radial direction is a rare earth magnet.   A composite claw in which any one of the claw pole type rotor according to claim 1, the claw pole type rotor according to claim 2, or the claw pole type rotor according to claim 3 is arranged in the direction of the rotation axis. Pole type rotor.

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