JPH05168221A - Hysteresis magnetic coupling - Google Patents

Abstract

PURPOSE:To enhance general purpose performance by arranging a pair of magnetic yokes to be fitted respectively and firmly on a pair of permanent magnets with multiples in the circumferential direction and for supporting a rotary shaft in a central hole, to be confronted with both the side surfaces of the rotor of hysteresis material. CONSTITUTION:In a hysteresis magnetic coupling 1, on a hub 3 formed with non-magnetic material fixed to be pressed in a rotary shaft 2, a disc-shaped rotor 4 formed with hysteresis material is firmly fitted. Besides, on the rotary shaft 2, a pair of magnetic yokes 5 formed with magnetic material, with the rotor 4 placed between the yokes 5, in the axial direction are fitted via a bearing, and on the magnetic yokes 5, a pair of permanent magnets 6 with 6 pales in the circumferential direction are fitted respectively and firmly. Then, between the side surfaces of the rotor 4 and the permanent magnets 6, specified air gaps are formed. Besides, on the outer peripheral surfaces of the pair of magnetic yokes 5, a case 7 formed with non-magnetic material is fitted, and the one-side opening end of the case 7 is fixed on the one-side magnetic yoke 5, and the other side opening end is fixed on the other side magnetic yoke 5 with a screw 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to hysteresis magnetic coupling, and more particularly to anisotropy of a rotor of a hysteresis material.

[0002]

2. Description of the Related Art A conventional hysteresis magnetic coupling is typically disclosed in Japanese Patent Application Laid-Open No. 2-299457. In the hysteresis magnetic coupling proposed in the publication, magnetic yokes to which permanent magnets are fixed are individually fitted to both side openings of a case made of a non-magnetic material. Further, a rotating shaft is rotatably supported via a bearing in a central hole formed in the pair of magnetic yokes. In the space between the permanent magnets arranged facing each other, a rotor made of a hysteresis material arranged with a predetermined air gap between each permanent magnet is arranged and mounted on the rotating shaft.

The permanent magnet is a rare earth magnet having different poles in the circumferential direction, and the rotor of the hysteresis material is
It is made of an anisotropic hard magnetic material having an easy axis of magnetization in the axial direction. In the hysteresis magnetic coupling having such a structure, since the rotor of the hysteresis material is magnetized by the action of the magnetic field of the permanent magnet, the rotation of the rotating shaft is transmitted to the case. Further, according to the description in the publication, the rotor is made of a hard magnetic material having magnetic anisotropy, and the permanent magnet is made of a rare earth magnet having a strong magnetic pole. However, a large transmission torque that has never been obtained can be obtained.

The applicant carried out the following trial production for the anisotropy of the rotor of such a hysteresis material. In other words, a permanent magnet with an outer diameter of 104 mm
・ A disk-shaped structure consisting of an inner diameter of 56 mm and a plate thickness of 4 mm, with a structure in which the polarities alternate with each other at 60 degree intervals equally divided into six in the circumferential direction, and the rotor made of hysteresis material has an outer diameter of 104 mm. -A disk-like shape having an inner diameter of 35 mm and a plate thickness of 6 mm was used, and was made of a hard magnetic material (for example, Alnico) having axial anisotropy.

The material characteristics of the rotor are as follows: coercive force Hc is 610 Oe, saturation magnetic flux density Br is 13350 G, and maximum magnetic energy product (BH) max is 6.2 MG · Oe.
Is. Furthermore, each air gap between the permanent magnet and the rotor of the hysteresis material was set to 0.5 to 0.6 mm.
The structure of the hysteresis magnetic coupling will be described in detail in the embodiments of the present invention.

The results obtained under such conditions are
The graph shown is the case of the axial anisotropy of FIG. In other words, the braking torque is 6 kgfcm at an operating angle of 0 degrees where the opposing permanent magnets are completely opposite to each other, and
Operating angle 60 where the opposing permanent magnets have the same poles
The maximum braking torque was 14.25 kgfcm.

[0007]

In the hysteresis magnetic coupling obtained by such an experimental result, the braking torque slightly increases depending on the operation angle. Therefore, the winding machine for applying tension to the yarn, the twisted yarn, the magnet wire, etc. When used as a load brake, it is suitable for fine adjustment of the braking torque, but if the range of the braking torque value is narrow, the versatility of the hysteresis magnetic coupling is poor and multiple models must be produced for each application, which is not economical. It was considered. In view of these problems, the present invention aims to increase the range of the torque value of the hysteresis magnetic coupling to improve versatility.

[0008]

In order to achieve the above object, the applicant noticed that the axial anisotropy of the rotor of the hysteresis material was changed to the radial anisotropy. In the present invention, the hysteresis magnetic coupling is a rotor of a hysteresis member made of an anisotropic hard magnetic material that is attached to the rotation shaft and has an easy axis of magnetization in a direction orthogonal to the axis of the rotation shaft. And a pair of permanent magnets facing the both side surfaces of the rotor with a predetermined air gap and having multiple circumferential poles. It is characterized in that it has a structure including a pair of magnetic yokes that rotatably support a rotating shaft.

[0009]

In the hysteresis magnetic coupling, since the rotor of the hysteresis material is magnetized in the magnetic field of the pair of permanent magnets, the rotation of the rotating shaft is caused by the magnetic force of the rotor, the permanent magnets and the magnetic yoke. It is transmitted to the member to which the yoke is fixed. Further, since the rotor of the hysteresis material is provided with radial anisotropy orthogonal to the axis of the rotating shaft, the torque value can be changed by rotating the relative position of the pair of permanent magnets arranged opposite to each other. The range fluctuates greatly.

[0010]

1 to 4 show an embodiment of a hysteresis magnetic coupling embodying the present invention. FIG. 1 is a sectional view, FIG. 2 is a side view, and FIG. 3 is a sectional view taken along line III-III in FIG. 4 is a sectional view taken along line IV-IV in FIG. FIG. 5 is a graph showing braking torque characteristics of the hysteresis magnetic coupling shown in FIGS. 1 to 4. The structure of the hysteresis magnetic coupling is different from the structure of the hysteresis magnetic coupling described in the related art only in the direction of the easy axis of magnetization of the rotor.

In the hysteresis magnetic coupling 1, a disc-shaped rotor 4 made of a hysteresis material is fixed to a hub 3 made of a non-magnetic material which is press-fitted and fixed to a rotary shaft 2. The rotor 4 is made of a hard magnetic material and is composed of a radial anisotropic material having an easy axis A (see FIG. 4) perpendicular to the axis of the rotary shaft 2. Also,
A magnetic yoke 5 made of a pair of magnetic materials in which the rotor 4 is sandwiched in the axial direction is fitted on the rotary shaft 2 via bearings, and these magnetic yokes 5 have six poles in the circumferential direction. The pair of permanent magnets 6 are individually fixed. Then, a predetermined air gap is formed between the side surfaces of the rotor 4 and the permanent magnet 6.

A case 7 made of a non-magnetic material is fitted on the outer peripheral surfaces of the pair of magnetic yokes 5. One open end of the case 7 is fixed to one magnetic yoke 5, and the other side of the case 7 is fixed. The open end is fixed to the other magnetic yoke 5 with a screw 8. Reference numeral 7a is a long hole into which the screw 8 is inserted, reference numeral 5a.
Is a screw hole into which the screw 8 formed in the magnetic yoke 5 is screwed, and reference numeral 5b is a mounting screw hole for fixing the hysteresis magnetic coupling 1 to a fixing member (not shown).

The applicant carried out the following trial production for the hysteresis magnetic coupling having such a structure. That is, like the conventional permanent magnet, the permanent magnet 6 has a disk-like shape having an outer diameter dimension of 104 mm, an inner diameter dimension of 56 mm, and a plate thickness of 4 mm, and the polarities are alternated at intervals of 60 degrees equally divided into six in the circumferential direction. With a different structure,
The rotor 4 made of hysteresis material has an outer diameter of 104 mm.
-A disk-like shape having an inner diameter of 35 mm and a plate thickness of 6 mm, and made of a hard magnetic material having radial anisotropy (for example, Alnico).

The material characteristic of the rotor 4 is the holding force Hc.
Is 600 Oe, the saturation magnetic flux density Br is 13050 G, and the maximum magnetic energy product (BH) max is 5.2 MG · O.
It is e. Furthermore, each air gap between the permanent magnet 6 and the rotor 4 is set to 0.5 to 0.6 mm. The results obtained under such conditions are shown in the graph shown in FIG. 5 for the case of radial anisotropy. That is, at an operating angle of 0 degrees, where the opposing permanent magnets 6 are completely opposite to each other, the braking torque is 0.84 kgfcm, and the operating angle 60 where the opposing permanent magnets 6 are completely the same and opposite. In degrees,
The braking torque reached a maximum of 28.5 kgfcm.

The method of operating the relative position of the permanent magnet 6 of the hysteresis magnetic coupling 1 is to rotate the case 7 and the other magnetic yoke 5 at an arbitrary angle with the screw 8 loosened from the one magnetic yoke 5. To do. Then, after adjusting the relative position of the permanent magnet 6, the screw 8 is tightened in the screw hole 5a to fix the case 7 and the one magnetic yoke 5.

[0016]

As described above, in the conventional hysteresis magnetic coupling in which the rotor has anisotropy in the axial direction,
While the braking torque value range was narrow from 6 kgfcm to 14.25 kgfcm, the hysteresis magnetic coupling of the present invention in which the rotor was provided with radial anisotropy had a braking torque value range of 0.84 kgfcm. It became wide from 28.5kgfcm. Therefore, since the versatility of the hysteresis magnetic coupling is increased, the production system can be changed from the small lot production of a large number of models to the large production of a small number of models, which is economical, and the hysteresis magnetic coupling can be provided at a low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hysteresis magnetic coupling.

FIG. 2 is a side view of a hysteresis magnetic coupling.

3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a graph of braking torque characteristics.

[Explanation of symbols]

 2 Rotation axis 4 Rotor 5 Magnetic yoke 6 Permanent magnet 7 Case A Easy magnetization axis

Claims (1)

[Claims] 1. A rotor made of an anisotropic hard magnetic material, which is attached to the rotary shaft and has an easy axis of magnetization in a direction orthogonal to the axis of the rotary shaft, and the rotor. A pair of permanent magnets facing each other on both sides with a predetermined air gap and having multiple poles in the circumferential direction, and the permanent magnets fixed to the permanent magnets individually to rotate the rotary shaft in the central hole. A hysteretic magnetic coupling comprising a pair of magnetic yokes supported on the.