JPH01303040A - Magneto motor - Google Patents

Abstract

PURPOSE:To dispense with a casing of a ferromagnetic material and to make a motor small in size and light in weight, by constituting a motor to whose stator permanent magnets are used with multipolar magnetization to an isotropic magnet material. CONSTITUTION:Let a stator 1 be of a ring-shaped isotropic magnet material with multipolar magnetization of more than three poles. To the other side a casing 2 is dispensed with and if a casing 2 is necessary, it is made of a non-magnetic material. When an anisotropic magnet is used, a casing 2 made of a ferromagnetic substance is necessary as the direction of anisotropy is radial. In this case, however, an isotropic magnet is used and no casing 2 of a ferromagnetic substance is necessary.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to improvements in magnetic motors.

[Background Art] With the recent development of OA equipment and FA equipment, many types of motors such as stepping motors, brushless motors, and coreless motors have come into use.
These motors have a permanent fa in the stator or rotor part.
E is often used, and in response to the demand for small and powerful motors, rare earth magnets such as Sm-C0 based magnets having magnetic anisotropy are preferred.

A motor using an anisotropic magnet stator usually has a casing made of a ferromagnetic material, generally iron, on the outside of the stator, and this is used as part of the magnetic circuit.

However, magnet motors are required to be even smaller and lighter. In order to meet this demand, it is desirable to not use the above-mentioned casing, or to form the casing with a light non-magnetic material (Δ-gain) such as aluminum or plastic.

[Problems to be Solved by the Invention] The objects of the present invention are to reduce the size of the above magnetic motor,
The object of the present invention is to provide a magnet type motor that satisfies the demand for weight reduction and does not have a casing made of ferromagnetic material.

[Means for Solving the Problems] The magnet type motor of the present invention is a motor using a permanent magnet in the stator portion, and the stator is made of an isotropic magnet material having a ring shape as shown in FIG. The stator (1) is multi-pole magnetized with 4 or more poles (4 in the example shown), and the stator (1) does not have a casing (2) on the outside, or if it does have a casing (2), it is a non-magnetic magnet. It is characterized by being made by hand.

The permanent magnet constituting the stator is preferably an isotropic magnet of the R-Fe-B system (R is a rare earth element represented by Nd). It can be easily manufactured by sintering the powder obtained by ultra-quenching or by molding it into a magnetic shape using a binder such as Plus Deck.

[Function] The stator, which is made by forming conventional anisotropic magnets into a ring shape and magnetized with multiple poles, is anisotropic in the direction or radially, so as shown in Figure 2A, the magnetic flux is Even on the outside,
It exists in a form that leaks outside the magnet. When the surface magnetic flux density is measured along the inner circumferential surface, a repeating graph as shown in No. 2N8 is obtained.

On the other hand, when the casing 2 made of ferromagnetic '4A lt is used, the magnetic flux leaking outside the magnet or the third
As shown in Figure A, it passes through this casing,
The magnetic flux density on the inner peripheral surface is improved as shown in FIG. 3B.

It is easily understood that if the casing is made of a ferromagnetic material, such improvement in characteristics cannot be obtained, as shown in d3.

On the other hand, when a stator is manufactured by magnetizing an isotropic magnet material with multiple poles according to the present invention, as shown in FIG. 4A, the magnetic flux is substantially inside the magnet and hardly leaks to the outside.
The surface magnetic flux density of the inner peripheral surface is as shown in FIG. 4B.

If a non-magnetic IJ I+ is used as a casing, the magnetic flux (J) will not be affected as shown in Figure 5A, and therefore the surface magnetic flux density will also be as shown in Figure 5B, as shown in Figure 4. B
The same is true. If an isotropic magnet is used and the casing material is ferromagnetic, the distribution of surface magnetic flux density will deviate from the sine curve, and the magnetic properties of the stator will rather deteriorate.

[Effects of the Invention] If a motor using permanent magnets in the stator is configured with multi-pole magnetization for each phase of isotropic magnets according to the present invention, it will be different from the case of using a stator of anisotropic magnets, which has been commonly used in the past. Therefore, there is no need to use a ferromagnetic ion casing. Therefore, it can be made without a casing, or with a non-magnetic material such as aluminum or plastic deck, and with a light monthly rate.

In this way, motors used in computer hard disk drives, floppy disk drives, peripheral devices such as printers, and facsimile machines can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the shape and magnetization state of a ring-shaped permanent magnet used in the magnetic motor of the present invention. 2 to 4 are conceptual explanatory diagrams of the state of magnetic flux and surface magnetic flux density in a ring-shaped permanent magnet,
In each figure, A represents the former, and B represents the latter. Second
The figure shows a conventional anisotropic magnet material magnetized, Figure 3 shows a case where it is housed in a casing made of ferromagnetic magnet material, and Figure 4 shows a ring-shaped isotropic magnet according to the present invention. Figure 5 shows a case in which the magnetic material is magnetized and placed in a casing. 1...Ring-shaped permanent magnet (stator) 2...Casing Patent applicant Jindo Special Steel Co., Ltd. Representative Patent attorney Souo Suki Figure 1 Figure 2A Figure 3A Figure 2B Go to Figure 4Figure 4B

Claims (2)

[Claims] (1) In a motor that uses permanent magnets in the stator,
The stator is an isotropic magnet material in the shape of a stator, magnetized with four or more multi-poles, and does not have a casing on the outside, or if it does, it is made of non-magnetic material. A magnetic motor characterized by: (2) R-Fe-B as a permanent magnet composing the stator
2. A magnetic motor according to claim 1, which uses isotropic magnets.