JPH08317581A - Armature of coreless motor - Google Patents

Abstract

PURPOSE: To provide the armature of a small-sized coreless motor which has raised efficiency by forming an equal, fine, and thin magnetic layer at the winding section of an armature by magnetic plating thereby reducing the magnetic resistance of a magnetic circuit, and concentrating magnetic fluxes to the winding section of the armature. CONSTITUTION: Permalloy alloy plating is applied to the opposite face from a field magnet 2 of an armature winding 1, which constitutes a rotor, by the laminate consisting of an amorphous alloy magnetic layer 12, 100μm or under in thickness made by plating method and an insulating layer 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an armature of a moving coil type coreless motor such as a cylindrical type or a flat type. By forming a thin magnetic layer on the armature winding portion by plating. The purpose of the present invention is to improve the efficiency by reducing the magnetic resistance of the magnetic circuit and concentrating the magnetic flux in the armature winding portion.

[0002]

2. Description of the Related Art A typical example of a rotor as an armature of a conventional coreless motor is shown in FIG.
There is one as shown in FIG. FIG. 4 is a cross-sectional view of the cylindrical coreless motor, in which the ironless core rotor coil 1 is arranged between the field magnet 2 and the main body case 3, and is supported from the rotating shaft 4 via the coil holding frame 5. Magnetic magnet 2
A current is supplied from the commutator 6 to the rotor coil 1 in the external magnetic field generated from the rotor coil 1 to cause the rotor coil 1 to rotate.

By the way, the magnetic circuit for forming this external magnetic field passes from the field magnet 2 magnetized in the radial direction, through the magnetic gap in which the rotor coil 1 is arranged, through the main body case 3, and again through the magnetic gap. A loop is drawn back to the magnetic magnet, and the size of this magnetic gap has a great influence on the rotation performance.

That is, the size of this air gap formed by the inner diameter of the coil and the magnet, the outer diameter of the coil and the case of the main body, and the thickness of the coil provides the rotational clearance of the rotor coil 1 and is inversely proportional to the permeance of this magnetic circuit. Therefore, the effective magnetic flux interlinking with the rotor coil is greatly affected.

Similarly, FIG. 2 shows a sectional view of a flat type coreless motor, in which a rotor 8 to which a flat coil 7 is fixed is shown.
Is placed between the field magnet 9 and the body case 10,
The rotating shaft 11 penetrates through the center thereof. And rotor 8
The magnetic gap interlinking with the core affects rotation performance in the same manner as the cylindrical type. Under such circumstances, there is a demand for a coreless motor that is compact and thin, and has high torque rotation performance.

From such a demand, a method in which magnetic powder is spliced and fixed to the armature winding portion can be considered. However, in a small coreless motor, the magnetic air gap is very small and the magnetic powder can be formed by the conventional method. If the body is attached and fixed, the magnetic layer becomes non-uniform and thick, and conversely the magnetic gap with the coil becomes large, and there is a problem that it becomes an obstacle to downsizing and thinning.

An object of the present invention is to solve the above-mentioned drawbacks. By forming a uniform and dense thin magnetic layer on the armature winding portion by magnetic plating, the magnetic resistance of the magnetic circuit can be improved. (EN) An armature for a small coreless motor with improved efficiency by reducing the magnetic flux and concentrating the magnetic flux in the armature winding portion.

[0008]

The present invention has been made to solve the above-mentioned conventional problems, and in the armature of the cylindrical coreless motor according to the present invention, the armature winding 1 constituting the rotor is Amorphous alloy magnetic layer with a thickness of 100 μm or less formed by plating on the surface opposite to the field magnet 2.
It is a laminated body composed of 12 and an insulating layer 13 and permalloy plated.

Further, in the armature of the flat coreless motor according to the present invention, the thickness of the film formed by the plating method is 100 μm on the surface of the armature winding 7 constituting the rotor, which is opposite to the field magnet 9. The following laminated body composed of the amorphous alloy magnetic layer 14 and the insulating layer 13 is permalloy plated.

Further, when the armature winding has a sufficient insulating film, it is not necessary to apply the insulating layer 13. Further, when the armature winding is plated with electricity while being energized as described above, anisotropy is imparted to the magnetic layer and the magnetic layer becomes uniform on the circumference.

[0011]

According to the present invention, the uniform thin magnetic layer formed by permalloy plating in the rotor is formed as a part of the core of the magnetic circuit. As a result, the magnetic flux links the rotor coil with the magnetic field magnet. Since a loop returning to the field magnet via the magnetic layer in the rotor is formed, the magnetic flux passing through the body case is reduced. Therefore, since the magnetic circuit is shortened and the permeance of the entire magnetic circuit is increased, the effective magnetic flux linking the rotor coils is increased, and the torque and output of the coreless motor are increased.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an armature of a cylindrical coreless motor according to an embodiment of the present invention. FIG. 2 is a sectional view showing an armature of a flat type coreless motor according to another embodiment of the present invention. FIG. 3 is a perspective view showing an armature of a cylindrical coreless motor according to an embodiment of the present invention.

As shown in FIGS. 1 to 3, the armature of the coreless motor according to the present invention has a structure in which the armature winding 1 constituting the rotor is provided with a permalloy on the surface opposite to the field magnet 2 by plating. (NiFe alloy) A soft magnetic layer is plated.

In the plating method, there are a vacuum deposition method, a sputtering method, an ion plating method, etc. as a dry plating method, and an electroless plating method, an electrolytic plating method, a coating method, etc. as a wet plating method. From the aspect, the wet plating method, which allows continuous production more easily than the dry plating method using a vacuum system, is superior. Therefore, in this example, the permalloy soft magnetic layer was plated by the electroplating method.

An example of the plating method will be described below. First, the surface of the coil is anodized to form an insulating layer. For anodic oxidation, a platinum plate was used as a cathode in a 10% aqueous solution of sulfuric acid, and an electric current of 30 mA was applied for 2 minutes to form an insulating layer.

Next, a magnetic layer of permalloy was formed on the anodized insulating layer by electroplating. The plating bath is
Ferrous sulfate heptahydrate 0.036 to 0.047 (mol / L), nickel sulfate hexahydrate 1.4 (mol / L), nickel chloride hexahydrate 0.4 (mol
/ L), boric acid 0.65 (mol / L), sodium saccharinate 6.
2 × 10 ^-3 (mol / L), sodium laurate 8.7 × 10 ^-4 (mol
/ L) was adjusted. The pH of the plating solution is a bath temperature of 40 ° C.
Adjusted to 2.2. In this way, the total film thickness is 10
A μm magnetic layer was formed.

FIG. 3 shows a perspective view when a cup-shaped coil is plated. FIG. 1 is applied to a cylindrical type and FIG. 2 is applied to a flat type, and FIG. 1 is an outer circumference of an ironless core rotor coil 1. The insulating layer 13 and the magnetic layer 12 are formed on the surface by the above-mentioned method. Similarly, in FIG. 2, the insulating layer is formed on the upper portion where the flat coils 7 are arrayed and fixed.
The rotor 8 is formed by forming 13 and the magnetic layer 14 and integrally molding the whole.

In the above structure, the thin magnetic layer formed by permalloy plating in the rotor is used as a part of the core of the magnetic circuit. As a result, the magnetic flux links the rotor coil with the magnetic field magnet, Since a loop returning to the field magnet via the magnetic layer in the rotor is formed, the magnetic flux passing through the body case is reduced. Therefore, the magnetic circuit is shortened and the permeance of the entire magnetic circuit is increased, so that the effective magnetic flux interlinking the rotor coils is increased. As a result, the torque and output of the coreless motor increased.

Although the insulating layer is formed in the above example, it is not necessary to form the insulating layer when the armature winding has a sufficient insulating film. Also, in the above example, the magnetic layer is isotropically used, so the main body case can be omitted, but if the armature winding is grounded by activation treatment and plated while energized, it will be magnetic. Anisotropy is imparted to the layers, they are plated uniformly on the circumference, and the body case can be used as the core material to increase efficiency.

[0020]

According to the present invention, as described in detail in the embodiments, by forming a uniform thin magnetic layer on the armature winding portion by plating, the magnetic resistance of the magnetic circuit is reduced and the magnetic flux is reduced. By concentrating on the winding portion, it is possible to provide a small and thin coreless motor armature with improved efficiency.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an armature of a cylindrical coreless motor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an armature of a flat coreless motor according to another embodiment of the present invention.

FIG. 3 is a perspective view showing an armature of a cylindrical coreless motor according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional cylindrical coreless motor.

FIG. 5 is a sectional view showing a conventional flat type coreless motor.

[Explanation of symbols]

 1,7 Rotor coil 2,9 Field magnet 3,10 Main body case 4,11 Rotating shaft 5 Coil holding frame 6 Commutator 8 Rotor 12,14 Magnetic layer 13 Insulating layer

Claims (5)

[Claims] 1. An armature for a coreless motor, characterized in that an armature winding constituting a rotor is plated with permalloy on a surface opposite to a field magnet. 2. A laminated body composed of an amorphous alloy magnetic layer having a thickness of 100 μm or less and an insulating layer is formed by plating on the surface of the armature winding constituting the rotor opposite to the field magnet. An armature for a coreless motor, which is characterized in that 3. The armature for a coreless motor according to claim 1, wherein the armature winding is plated while being energized during plating. 4. The armature winding constituting the rotor is wound so as to form a cylindrical shape.
The armature of the coreless motor according to any one of 3 above. 5. The armature winding constituting the rotor is wound so as to form a flat shape.
The armature of the coreless motor according to any one of 3 above.