JPS6084964A - Magnetic coupler - Google Patents

Abstract

PURPOSE:To enable to generate high torque in a small size by generating magnetic coupling forces on the both inner and outer peripheral surfaces of a cylindrical portion of a rotor. CONSTITUTION:Poles 14, 14' are provided on the inner periphery of a yoke 12 which contains a coil 13. Nonmagnetic shielding rings 15 are bonded to the ends of the poles 14, 14'. When the coil 13 is energized, magnetic powders 24, 21 sealed in air gaps on the inner and outer peripheral surfaces of the cylindrical portion of a rotor 18 are magnetized. The rotation of the rotor 18 is restricted by shearing resistance which is acted among the particles of the powders 24, 21, and elements to be braked connected through a rotational shaft 19 to the rotor 18 are accordingly braked.

Description

Detailed Description of the Invention The present invention utilizes the shear resistance of the powder generated by enclosing magnetic powder in a gap formed by a pair of rotating bodies or a rotating body and a fixed body and magnetizing the powder. torque transmission,
The present invention also relates to a magnetic coupling device that performs a braking action.

This type of coupling device is superior to friction-type disc clutches or brakes in that it has slip resistance characteristics, but the torque capacity for the same outer diameter is about 1/3 to 1/4, and for the same torque Therefore, it becomes large in size.

It is an object of the present invention to provide a magnetic coupling device of this type which is compact and capable of generating high torque.

First, let's look at what is generally known as this type of device.
The diagram will be explained. In the figure, 1 is a yoke that accommodates a coil 2 and is supported by left and right brackets 3 and 4. 5
is an outer rotating body connected to the rotating shaft 6 on the right side wall and has a cylindrical portion 7, which is magnetically divided into left and right sides by a non-magnetic blocking ring 8 interposed in the center. Ru. The rotating shaft 6 is supported by the right bracket 4 via a bearing 9. 1
゜ is an inner rotating body surrounded by an outer rotating body 5, and a gap exists between the outer circumferential surface and the inner circumferential surface of the cylindrical part 7 of the rotating body 50,
Magnetic powder 11 is sealed within this gap. The illustrated device is used as a brake, and the inner rotating body 1o is integrally connected to the left bracket 3 in order to function as a brake. By fixing it in place on the machine, it will not rotate during operation. In this case, the rotary shaft 6 is not a braked shaft, but is connected to a braked body (not shown).

The conventional coupling device is constructed in this way, and when a current is supplied to the coil 2, a magnetic flux is generated whose magnetic path is indicated by a broken line in the figure.
A magnetic attraction force is generated between the particles of the magnetic powder 11 and between the powder and the peripheral wall constituting the gap accommodating the powder, which in turn generates shear resistance between the magnetic powder particles, and the inner rotating body 1o, thus Braking is applied to a braked body connected to the rotating shaft 6 integral with this.

In such a conventional coupling device, the contact surface of the inner rotating body 1° with the magnetic powder 11 is only the outer circumferential surface of the rotating body, so the restraining force on the rotating body 10 when the magnetic powder 11 is magnetized, and therefore Only a small amount of braking force can be exerted.

In view of this, the present invention doubles the braking force or torque capacity when used as a clutch by creating a magnetic coupling force on the outer surface of the member corresponding to the inner rotating body. An embodiment in which the present invention is implemented in a slave will be described with reference to FIG. In the figure, reference numeral 12 denotes a yoke that accommodates the coil 13, and magnetic pole portions 14, 14 are provided on the inner circumference of the yoke, extending from both sides toward the center, respectively.
' has the same structure as the conventional yoke described above, but in this embodiment, a non-magnetic cutoff ring I5 is joined across the tips of both magnetic pole parts, and this ring and the inner circumferential surfaces of both magnetic pole parts are connected. It constitutes one wall surface of a cavity in which magnetic powder, which will be described later, is enclosed. Reference numerals 16 and 17 refer to left and right brackets made of non-magnetic material, which support both ends of the yoke 12 at their peripheral edges, and one bracket is fixed in place on the machine in which the brake is used and does not rotate during operation together with the yoke part. It looks like this. 8 is a rotating body with a T-shaped cross section, which is integrated with the rotating shaft 19 at the boss part of the disc-shaped part, and the central part of the cylindrical part and the part from this part to a part of the disc-shaped part are made of non-magnetic material. This part is formed by the magnetic isolation ring 2
0 and the outer peripheral surface of the cylindrical part and the magnetic pole part 14.1
A gap is formed between the inner circumferential surfaces of 4', and the magnetic powder 21 is filled in this gap. The rotating shaft 19 has bearings 22, 22'
supported by each bracket 16,17 via.

Note that in the above, the non-magnetic blocking ring 20 is the rotating body 18.
Although it is possible to provide it only in the center of the cylindrical part, it is advantageous to provide it over a part of the disc-shaped part as in the embodiment, as it helps to reduce leakage magnetic flux when the magnetic powder is magnetized. It is. 23. 23' is an annular magnetic pole body fixed to the inside of 16.
A gap is formed between the inner circumferential surface of the cylindrical part and the magnetic powder 24 is sealed within this gap. 25.25' and 26
．． 26' is a seal, and the seal 25. 25' is inserted into the recess on the inner surface of the magnetic pole bodies 22 and 227, and lightly contacts the disc-shaped part of the rotating body 18.
The seals 25 and 22' are fitted into recesses on the inner circumferential surfaces thereof, and come into contact with the protrusion of the rotary shaft 19, and together with the seals 25 and 25' prevent the magnetic powder 24 from flowing out.

The embodiment of the present invention is configured as described above, and when power is supplied to the coil 13, a magnetic flux flows in the magnetic path shown by the broken line, and the magnetic flux is enclosed in the air gap on the outer peripheral surface of the cylindrical portion of the rotating body 18. Each magnetic powder 24, 21 is magnetized, and the rotation of the rotating body 18 is restrained by the shear resistance acting between the particles of these magnetic powders. Braking is applied to the braked body.

The embodiment has been described for the case of a brake, but when used as a clutch, the yoke side is not fixed, and if this yoke side is hardened, it is connected to the driven side, and at the same time, the rotating shaft 19 on the other rotating side is connected to the driving side. By connecting,
When supplying current to the coil 13 or cutting off the power supply,
Needless to say, power transmission is performed or interrupted.

In the present invention, the rotating body 18 is formed to have a T-shaped cross section, and the left and right cylindrical wings, which are the left and right cylindrical wings, are magnetically separated from each other by a non-magnetic blocking ring, and the rotating body is shaped like a disk. A gap is formed between the outer circumferential surface of the magnetic pole body and the inner circumferential surface of the cylindrical portion of the rotary body, and magnetic powder is enclosed in this gap, and at the same time the magnetic powder is filled in the rotary body. Magnetic powder is also enclosed in the gap formed between the outer peripheral surface of the cylindrical part and the magnetic pole part connected to the yoke, so that when the magnetic powder is magnetized, it The operating gap that generates the binding force is in two places on the inner and outer circumferential surfaces of the cylindrical part of the rotating body, and magnetic coupling force is generated on both the inner and outer circumferential surfaces of the cylindrical part of the rotating body. Compared to the case where the magnetic coupling force is generated only at one place on the inner circumferential surface of the outer rotating body shown in Fig. 1, the average diameter of the peripheral wall that makes up the gap, the shear resistance due to magnetization, and the For the same value, it is possible to have twice the restraining force, and thus the braking force or torque capacity, and it is possible to provide a small magnetic coupling device with a large capacity, and furthermore, the rotating body is formed with a T-shaped cross section. Therefore, the cylindrical part of the rotating body is supported by the disk-shaped part at the center, and in other words, the cylindrical part of the rotating body is dimensionally distributed evenly to the left and right with respect to the supporting part. This cylindrical part is easy to maintain roundness and concentricity throughout the support part, and therefore, in terms of accuracy, it is easy to machine the rotating body, and at the same time, the machining cost can be reduced. Although this type of electromagnetic coupling device can be used in a slip state, the amount of heat generated in the operating gap that encloses the magnetic powder is large, especially when the device according to the present invention generates a large amount of heat. The heat flow path for dissipating this generated heat is symmetrical, so the brackets on both sides are divided equally into two, which reduces the heat dissipation ability. But it is advantageous.

[Brief explanation of the drawing]

FIG. 1 is a front view with the upper half of a conventional magnetic coupling device in cross section, and FIG. 2 is a front view of an embodiment of the present invention with the upper half in cross section. 12...Yoke, 14, 14'...Magnetic pole part, 15, 20...Nonmagnetic cutoff ring, 1
8...-Rotating body, 19... Rotating shaft, 21.24.
...Magnetic powder, 23, 23'...Magnetic pole body. Applicant: Shinko Electric Co., Ltd. Agent: Attorney: Haruya Fuji

Claims (1)

[Claims] A yoke that has a pair of circular magnetic pole parts with a non-magnetic blocking ring located in the center in between and abutting their tips. A gap for enclosing magnetic powder is formed between the outer periphery of the cylindrical part and the above-mentioned magnetic pole part. and a rotating body connected to the rotary body, and fixed to brackets located on the left and right sides of the disc-shaped portion of the rotary body and supporting the yoke, and having an outer circumferential surface and an inner circumferential surface of the cylindrical portion of the rotary body. 1. A magnetic coupling device comprising a pair of magnetic pole bodies forming a gap for enclosing magnetic powder therebetween, and generating a magnetic coupling force on the inner and outer surfaces of a cylindrical portion of a rotating body.