JPH1080079A - Reluctance motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cogging torque and obtain good characteristics having little torque ripples by shifting a plurality of completed products of rotor cores to a rotating direction and integrally constituting ion an axial direction. SOLUTION: Permanent magnets 4a and 4b embedded inside a rotor 1 are divided into two in axial direction, and rotor core sheets are laminated in alignment with the length in the axial direction of the permanent magnets 4a and 4b and a rotor core 3 is obtained. Permanent magnets 4a and 4b divided into the laminated rotor core 3 are respectively embedded to integrally form a core and completed rotor cores 3a and 3b are obtained. These two completed products 3a and 3b are deviated in rotating direction, jointed together, and a rotor shaft 2 is inserted by press fitting or other means to obtain the rotor 1. In this way, the quantity of magnetic flux flowing from stator side to rotor side is smaller at the side of rotor core completed product 3a and becomes larger at the side of rotor core completed product 3b, and it is averaged in the whole of rotor 1 and the cogging torque becomes smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor utilizing reluctance torque by providing a plurality of permanent magnets or a plurality of slits in a rotor axial direction.

[0002]

2. Description of the Related Art Conventionally, a rotor main body in which a permanent magnet is embedded in a rotor main body made of a material having high magnetic permeability such as iron has been known.

FIG. 6 shows a rotor with a permanent magnet having a two-layer structure developed by the present inventors in order to effectively utilize reluctance torque (Japanese Patent Application No. 7-134023).

The rotor 1 according to the prior invention has a rotor shaft 2 at the center, and four sets of permanent magnets 4a and 4b arranged at intervals in two layers per pole in the rotor radial direction on a rotor core 3 made of iron. The permanent magnets 4a, 4
b is adjacently arranged so that the S pole and the N pole are alternately arranged;
Each of them is formed in an arc shape that is convex in the centripetal direction of the rotor.

[0005] The iron rotor core 3 is formed by laminating a large number of core sheets having holes. The iron rotor core 3 is laminated with the positions of the holes aligned, and the arc-shaped permanent magnet is inserted and embedded.

[0006]

In the configuration of the above-mentioned prior invention, the number of man-hours for assembling the rotor is the smallest, and the rotor can be manufactured at low cost. However, the slit provided in the rotor is straight and parallel to the rotor shaft. Because
There was a problem that the cogging torque fluctuation during rotation of the rotor became large due to the positional relationship with the stator.

[0007] As an example, Fig. 7 shows the result of fluctuation of torque ripple by magnetic field analysis in the configuration of the present invention.
As is clear from this data, a large torque variation of about 80% is shown.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the first invention of the present application is directed to a permanent magnet embedded type reluctance motor having a permanent magnet embedded inside a rotor core in an axial direction. The permanent magnet divided into a plurality of pieces is embedded in a rotor core similarly divided into a plurality of pieces in the axial direction, and the plurality of finished rotor cores are shifted in the rotor rotation direction to be integrally formed in the axial direction.

According to the present invention, since the position of the slit portion provided on the rotor and the position of the teeth of the stator are not simultaneously at the same position, cogging is reduced and a reluctance motor having good characteristics with little torque ripple is provided. can get.

In order to solve the problems of the above-mentioned prior invention, a second invention of the present application relates to a reluctance type synchronous motor having a rotor provided with a plurality of slits, wherein the rotor comprises a plurality of completed rotor cores. The finished product has the slit position shifted in the rotation direction and is integrally formed in the axial direction.

According to the present invention, since the position of the slit portion provided on the rotor and the position of the teeth of the stator are not simultaneously at the same position, cogging is reduced, and a reluctance motor having good characteristics with little torque ripple is provided. can get.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention is directed to a reluctance motor having a rotor configured by shifting a plurality of completed rotor cores in the rotation direction.

In a reluctance motor having a permanent magnet, the permanent magnet is divided into a plurality in the axial direction of the rotor.
A plurality of rotor core finished products obtained by embedding permanent magnets in a laminate of rotor core sheets in accordance with the axial length of each permanent magnet are integrally formed by shifting in the rotation direction to obtain a rotor. Also, a reluctance motor having no permanent magnet has the same configuration as described above except for having no permanent magnet.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) As shown in FIG.
The permanent magnets 4a, 4b embedded in the
The rotor core sheet is laminated and the rotor core sheet is laminated according to the axial length of the divided permanent magnets 4a and 4b. The completed rotor cores 3a and 3b are obtained by embedding the permanent magnets 4a and 4b divided into the laminated rotor core 3 and integrally forming them.

The two rotor core finished products 3a and 3b are joined while being shifted in the rotation direction, and the rotor shaft 2 is inserted by means such as press fitting to obtain the rotor 1.

FIG. 3 is an explanatory diagram showing the positional relationship between the rotor and the stator in the completed rotor core product 3a in the rotational direction. FIG. 4 is an explanatory view of the positional relationship between the rotor and the stator in the completed rotor core product 3b in the rotational direction. This FIG. 3 and FIG.
At a certain rotational position, the rotor 1 in which the rotor core finished products 3a and 3b are integrally formed has a positional relationship with teeth and slots on the stator side.

As shown in FIG. 3, when the permanent magnets 4a and / or 4b match the positions of the teeth 6 of the stator, the magnetic resistance increases and the magnetic flux 8 decreases. At this time, on the other hand, the rotor core finished product 3b side is shown in FIG.
Since the positions of the teeth 6 of the stator and the permanent magnets 4a and / or 4b are shifted from each other, the magnetic resistance decreases and the magnetic flux 8 increases.

At this time, the amount of magnetic flux flowing from the stator side to the rotor side at the time of the positional relationship of FIGS.
The side becomes larger, and the entire rotor 1 is averaged. Although not shown, the amount of magnetic flux flowing from the stator side to the rotor side at the next point in time is large on the rotor core completed product 3a side and small on the rotor core completed product 3b side, and the rotor 1 as a whole is also averaged. You.

Since the change in the amount of magnetic flux becomes the cogging torque, the configuration of the present invention can provide a reluctance motor having a small cogging torque.

FIG. 5 shows the result of fluctuation of torque ripple by magnetic field analysis in the configuration of the present invention. As is clear from this data, the torque fluctuation is about 35%,
This is greatly improved over the conventional example shown in FIG.

Although the above embodiment has been described as a rotor in which two completed rotor cores are integrally formed, a rotor in which three or more completed rotor cores may be integrally formed may be used. If three or more rotor core finished products are shifted in the same rotation direction, or half of the rotor cores are shifted in the same rotation direction, and the other half are shifted in the opposite direction,
Further, the cogging torque is reduced, and the torque fluctuation is also reduced.

(Embodiment 2) As shown in FIG. 2, a completed rotor core product 3a obtained by laminating core sheets provided with a plurality of arc-shaped slits, and a completed rotor core product 3b obtained in the same manner Are shifted in the rotational direction, and the rotor shaft 2 is inserted by means such as press fitting to obtain the rotor 1.

According to this configuration, the permanent magnets 4a and 4b in the first embodiment are merely replaced with the slits 5, so the first embodiment
As in the above, a reluctance motor having a small cogging torque can be obtained.

Although the above embodiment has been described as a rotor in which two completed rotor core products are integrally formed, a rotor in which three or more finished rotor core products are integrally formed may be used. If three or more finished rotor cores are shifted in the same rotation direction, or half of the rotor cores are shifted in the same rotation direction and the other half are shifted in the opposite direction, the cogging torque is further reduced and the torque fluctuation is reduced. Is also smaller.

[0026]

As is clear from the description of the above embodiment,
By using a reluctance motor having a rotor integrally formed by shifting a plurality of completed rotor cores in the rotation direction, a cogging torque is small, and a reluctance motor having small torque ripple during rotation is provided.
Good characteristics with reduced noise and vibration during motor rotation can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rotor showing an embodiment of the present invention.

FIG. 2 is a perspective view of a rotor showing another embodiment of the present invention.

FIG. 3 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 5 is a characteristic diagram based on a magnetic field analysis of the embodiment of the present invention.

FIG. 6 is a perspective view of a conventional rotor.

FIG. 7 is a characteristic diagram based on a magnetic field analysis of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 rotor 2 rotor shaft 3 rotor core 3a, 3b completed rotor core 4 permanent magnet 5 slit 6 stator tooth 7 slot 8 magnetic flux β

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Ito 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Naoyuki Kadoya 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] In a permanent magnet embedded type reluctance motor having a permanent magnet embedded in a rotor core in an axial direction, a permanent magnet divided into a plurality in the axial direction is embedded in a rotor core divided into a plurality in the axial direction. A reluctance motor having a rotor in which the plurality of completed rotor cores are integrally formed in the axial direction by being shifted in the rotor rotation direction. 2. A reluctance type synchronous motor having a rotor provided with a plurality of slits, wherein the rotor is composed of a plurality of completed rotor cores, and each completed rotor core is formed by shifting the slit position in a rotational direction to an axial direction. A reluctance motor characterized by being integrally formed with the motor.