JP2001086671A - Magnet for motor, and its fixation method, and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of fixing a permanent magnet which can easily unite the divided magnet pieces, in a permanent magnet for a split type of motor used for IPM(interior permanent magnet motor), SRM(synchronous reluctance motor), etc., and a motor which reduces eddy current loss. SOLUTION: A plurality of magnet pieces can be bound firmly by winding the band 3 of high-strength fibers such as, for example, aramide fibers, the ends of band of which are impregnated with resin in advance on the required outside periphery of a magnet being assembled by abutting the plural magnet pieces into specified form, and making the ends overlap each other, and fastening it thereby uniting the plural magnet pieces. Even if the magnet is magnetized after assembly, they never break by the resiliency of the fellow magnets. The eddy current loss can be reduced by increasing the number of divisions, and a motor where the eddy current loss is reduced can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a motor magnet in which a plurality of divided magnets are integrated and incorporated into a motor. The present invention relates to a motor magnet having a surface fastened, a method for fixing the magnet, and a motor.

[0002]

2. Description of the Related Art Electric vehicles (EVs) are the next generation of vehicles.
As the development and commercialization of the motors are progressing, motors in particular are required to be small and light, have high output, high efficiency, and high reliability.

At present, as a motor for an EV, a so-called IPM (Interior Permanent Magnet Motor) or SRM (Synchr) is used in which a permanent magnet is embedded in a rotor formed of a silicon steel plate or the like.
A brushless motor called onous Relutance Motor) has been developed.

[0004] When an AC magnetic field is applied to the magnet, an eddy current is generated in the magnet and eddy current loss occurs. Therefore, permanent magnets for IPM
It is necessary to reduce the eddy current generated in the magnet, and therefore, the magnet for the motor has been changed from an integrated product to a divided product.

[0005]

In the case of inserting the divided magnets into the rotor, inserting the divided magnet pieces one by one is troublesome and has a problem of low productivity. Therefore, it is necessary to integrate them in advance in order to make them easy to insert. Conventionally, magnet pieces were fixed one by one with an adhesive.

[0006] However, if the magnets are magnetized after they are bonded and integrated, a repulsive force is generated between the magnets, and there has been a problem that the bonding may be released from a place where the bonding force is weak.

An object of the present invention is to provide a motor magnet which eliminates the drawbacks of the split-type motor permanent magnets used in the IPM, SRM, etc., and which can easily integrate the divided magnet pieces. The purpose of the present invention is to provide a method for fixing the motor, and to provide a motor with reduced eddy current loss.

[0008]

As a result of various studies for the purpose of easily integrating the divided magnet pieces, the present inventors have found that a plurality of magnet pieces are arranged in contact with each other and assembled into a desired shape. Using a high-strength fiber band such as aramid fiber, impregnate the end of the fiber band with a resin, and wrap it around the outer surface. Even when the integrated magnet body is magnetized and embedded in the rotor, or when the integrated magnet body is magnetized after being embedded in the rotor, there is no problem such as decomposition by the repulsion of the magnets And found that they can be integrated.

[0009] Further, the inventors dispose a high-strength fiber band on the inner peripheral surface of a frame made of a fiber-reinforced resin material, insert a plurality of magnet pieces into the frame, and assemble the magnet into a required shape. By fastening the required outer peripheral surface of the body with the high-strength fiber band, that is, by integrating the high-strength fiber band and the frame body by heat welding, the magnet body is fixedly housed in a frame body made of a fiber-reinforced resin material. By embedding the frame in the rotor,
The present inventor has found that it is easy to assemble the motor and completed the present invention.

[0010] Further, the present inventors provide a non-conductive resin layer on the surface of the divided magnet pieces as a rare earth magnet such as Fe-BR system, so that the magnet pieces can be embedded in a rotor, for example, in an IPM rotor. The generated eddy current can be significantly reduced,
It has been found that the performance improvement of the can be realized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when an AC magnetic field is applied to a permanent magnet, an eddy current is generated in the magnet and an eddy current loss occurs. In the case of a magnet, a required number of the bar-shaped magnets 1 are arranged and assembled into the plate-shaped magnet 2 with the long side surface of the bar-shaped magnet 1 having the short side length as the longitudinal direction as the contact surface.

The above-mentioned divided bar-shaped magnets 1 must be electrically insulated from each other.
Are coated with, for example, a non-conductive epoxy resin or the like, and are configured to ensure electrical insulation from each other at the time of contact.

[0013] At the outer peripheral portion of the end face of the rod-shaped magnet 1 assembled in a plate shape,
The high-strength fiber band 3 is wound, for example, using aramid fiber woven in a tape shape, and an overlapping portion of the end of the fiber band 3 is impregnated with, for example, an epoxy resin in advance to form a joining portion 3a, and the end surface outer peripheral portion After being wound around, the joint 3a can be fastened by heat welding, and the bar-shaped magnet 2
Can be integrated.

A plate-like magnet 2 formed by fastening with a high-strength fiber band 3
After the required magnetization, the can be fitted into the required hole of the rotor of the IPM, for example. Further, as shown in FIG. 2, when the shape of the hole is not rectangular, a frame 4 having a required shape is prepared as a spacer so as to fill a space between the shape of the hole and the rectangle, and the height 4 is provided on the frame 4. The plate-like magnet 2 fastened by the strength fiber band 3 can be fitted.

[0015] Further, the frame 4 is, for example, FRP (Fiber Reinf
orced Plastic) method, CFRP method, resin molding, and high strength fiber band 3 made of aramid fiber is inserted into this frame and integrated, and bar magnet 1 is inserted into this to form plate magnet 2 Then, it can be embedded in the rotor together with the frame 4. In the configuration example of the IPM shown in FIG. 3, the IPM 5 is composed of the split core 6 and the rotor 7 arranged inside the core.
And embedded in each part together with the plate-shaped magnet or the frame.

[0016] In the present invention, the high-strength fiber band has a high strength that keeps a restraining force against the repulsive force after magnetization, -40 ° C to + 16 ° C.
It is desirable to have excellent properties such as low elongation, light weight, heat resistance, impact resistance, chemical resistance, non-conductivity, vibration damping property, etc. Besides, PBO (polyoxadol), polyethylene,
An organic high-strength fiber band such as a polyacrylate resin can be adopted.

[0017] In the present invention, any known material can be used for the magnet, and high performance rare earth magnets such as Fe-BR based sintered magnets and Fe-BR based bonded magnets can be used. As described above, the surface of each magnet is coated with a film capable of ensuring electrical insulation.

[0018]

Example 1 The plate-shaped magnet shown in FIG. 1 was made of a Fe-BR based sintered magnet, and was divided into three, five, and seven divisions. Resin is formed and electrically insulated from each other. As shown in FIG. 1, the plate-like magnets assembled in a divided manner were fastened and integrated by a high-strength fiber band 3 made of aramid fiber.

When the eddy current loss applied to the plate magnet embedded in the core of the IPM is model-analyzed by the finite element method, the loss is compared by the number of divisions. No division: 3 divisions: 5 divisions: 7 divisions = 24 :
6: 2: 1, and it is clear that the eddy current loss can be reduced by increasing the number of divisions.

[0020]

According to the present invention, even if a permanent magnet for a motor such as an IPM or SRM is divided, it can be easily assembled and integrated, and can be easily embedded as an integral magnet in a required hole of a motor core. It is possible.

[0021] Further, according to the present invention, the divided magnet pieces can be easily integrated and easily housed in required holes of the motor core, so that eddy current loss is reduced and high performance IPMs and SRMs are provided.
And other motors can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective explanatory view showing a motor magnet according to the present invention.

FIG. 2 is a perspective explanatory view showing an example of a method for fixing a magnet for a motor according to the present invention.

FIG. 3 is an explanatory diagram illustrating a configuration example of an IPM.

[Explanation of symbols]

 1 Bar magnet 2 Plate magnet 3 High strength fiber band 3a Joint 4 Frame 5 IPM 6 Split core 7 Rotor 8 Rotor magnet

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsutoshi Natsume 2-15-17 Egawa, Shimamoto-cho, Mishima-gun, Osaka F-term in Sumitomo Special Metals Co., Ltd. Yamazaki Works (reference) 5H621 AA03 GA01 GA04 HH01 JK03 5H622 AA03 CA02 CA07 CA13 CB01 CB05 DD02 PP03 PP07 PP16 PP17 PP19 QA06

Claims (8)

[Claims] 1. A motor magnet in which a required outer peripheral surface of a magnet body composed of a plurality of magnet pieces is integrally fastened with a high-strength fiber band. 2. A motor magnet in which a required outer peripheral surface of a magnet body composed of a plurality of magnet pieces is fastened with a high-strength fiber band and housed in a frame made of a fiber-reinforced resin material. 3. The motor magnet according to claim 1, wherein the magnet piece is a rare earth magnet having a nonconductive resin layer on a surface. 4. The motor magnet according to claim 1, wherein the high-strength fiber band comprises an organic high-strength fiber band, and the fiber is impregnated with a resin and fastened. 5. A method for fixing a magnet for a motor, in which a plurality of magnet pieces are arranged in contact with each other and a required outer peripheral surface of a magnet body assembled in a required shape is fastened with a high-strength fiber band and integrated. 6. A motor for accommodating a plurality of magnet pieces in contact with each other and assembling the magnet body into a desired shape, fastening a required outer peripheral surface of the magnet body with a high-strength fiber band, and storing the magnet body in a frame made of a fiber-reinforced resin material. How to fix the magnet. 7. A required magnet body assembled into a required shape by arranging a high-strength fiber band on an inner peripheral surface in a frame made of a fiber-reinforced resin material and inserting and arranging a plurality of magnet pieces in the frame body. A method for fixing a magnet for a motor, the outer peripheral surface of which is fastened by the high-strength fiber band. 8. A required magnet outer surface of a magnet body composed of a plurality of magnet pieces is fastened by a high-strength fiber band, or a magnet for a motor housed in a frame made of a fiber-reinforced resin material is further inserted into the rotor. Motor embedded in.