JP2002130342A - Non-excitation actuated type electromagnetic brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend life expectancy of control parts by getting rid of wear, eliminate noise emitted from the control parts, and simplify structurally by removing moving elements. SOLUTION: An electromagnetic brake 11 comprises a brake moving member 12 of magnetic materials fixed on a rotating shaft 4, an electromagnetic brake body 15 composed of a yoke member 17 having a coil winding 16, permanent magnets 18a, 18b arranged in a magnetic circuit formed by the electromagnetic brake body 15 and the brake moving member 12, wherein magnetic fluids 19a, 19b are interposed or filled between the electromagnetic brake body 15 and the brake moving member 12, the magnetic force in excitation status of the electromagnetic brake body 15 is actuated in opposite to the direction of a magnetomotive force of the permanent magnets 18a, 18b, and then the electromagnetic brake 11 is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-excitation type electromagnetic brake, and more particularly, to a non-excitation type electromagnetic brake incorporating a permanent magnet.
The present invention relates to a non-excitation operation type electromagnetic brake that performs a braking operation via a magnetic fluid.

[0002]

2. Description of the Related Art A conventional non-excited operation type electromagnetic brake is shown in FIG. That is, in FIG. 5, an electromagnetic brake 1 is fixed to an output rotation shaft 4 of a motor 3, a brake disk 2 as a brake movable portion, and a fixed yoke member 7 having a coil winding 6.
An electromagnetic armature 8 integrated with a brake lining material 8a;
And a spring 9 for urging the electromagnetic brake main body 5 away from the electromagnetic brake main body 5 to operate the brake. (Note that the brake lining material 8a may be integrated with the brake disk 2.)

When the coil winding 6 is not energized, the spring 9
The armature 8 is separated from the electromagnetic brake main body 5 by the urging force, and the brake lining material 8a attached to the armature 8 is brought into contact with the brake disk 2 to generate a braking force by friction. The output rotary shaft 4 of the motor 3 is braked. When the coil winding 6 is energized, the armature 8 is attracted to the electromagnetic brake main body 5 against the urging force of the spring 9, and the brake lining material 8a is separated from the brake disk 2. The rotating shaft 4 is released from the brake.

In this electromagnetic brake 1, two or more pins 10 are erected on the yoke member 7, and the pins 10 are
The armature 8 is engaged with a pin hole 8b provided in the armature 8 to prevent the armature 8 from rotating together with the brake disk 2 and guide the armature 8 so as to be slidable in the rotation axis direction.

[0005]

However, in such a conventional non-excited operation type electromagnetic brake 1, the braking force fluctuates due to a temporal change in the surface condition of the brake lining material 8a due to frictional braking. At the same time, there is a life due to the wear of the brake lining material 8a.
Due to friction, a noise is generated during braking, and when the armature 8 is excited and attracted, the armature 8 comes into contact with the yoke member 7 on the electromagnetic brake main body 5 side to generate a noise.

Further, since the armature 8 has a backlash in the rotating direction, when the electromagnetic brake 1 is braked and held, the rotating shaft 4 is loose. In particular, when exciting, it is necessary to consider that there is a certain amount (not negligible) of air gap in the magnetic circuit that generates the attraction force in the electromagnetic brake 1 and that the balance between the attraction force and the biasing force of the spring 9 is taken into consideration. There was a problem that the design of the magnetic circuit became very complicated, for example, due to the fact that the gap was finely adjusted.

[0007] The present invention has been made in view of such a point,
An object of the present invention is to provide a non-excited operation type electromagnetic brake which solves the above-mentioned problem, eliminates wear of the braking portion, prolongs its life, and eliminates noise generated from the braking portion.

It is another object of the present invention to provide a non-excited operation type electromagnetic brake which has a simple structure and a small number of components, while eliminating a movable portion in terms of structure in braking.

[0009]

To achieve the above object, the present invention provides a brake movable member made of a magnetic material and fixed to a rotating shaft such as an output rotating shaft of a motor, and a coil winding. A non-excited operation type electromagnetic brake comprising: an electromagnetic brake main body composed of a yoke member having: and a permanent magnet disposed in a magnetic circuit formed by the electromagnetic brake main body and the brake movable member. It is as follows.

A magnetic fluid is interposed or filled between the electromagnetic brake main body and the brake movable member, and the direction of the magnetic force in the excited state of the electromagnetic brake main body acts in a direction opposite to the direction of the magnetomotive force of the permanent magnet. Thus, the electromagnetic brake is released.

The permanent magnet is an electromagnetic brake disposed on the brake movable member side.

The permanent magnet is an electromagnetic brake disposed on the electromagnetic brake main body side.

[0013] An electromagnetic brake in which a gap is formed in a part between the electromagnetic brake main body and the brake movable member to be filled with the magnetic fluid.

A guide rail made of a magnetic material, an electromagnetic brake body attached to a bogie made of a non-magnetic material and made of a yoke member having a coil winding, and a magnetic circuit formed by the electromagnetic brake body and the guide rail A non-excited operation type electromagnetic brake, comprising a permanent magnet disposed in the electromagnetic brake main body therein, and the carriage on which the electromagnetic brake main body is mounted is movably disposed on the guide rail via a roller. A magnetic fluid is interposed between the electromagnetic brake main body and the guide rail, and a magnetic force direction in an excited state of the electromagnetic brake main body is made to act in a direction opposite to a direction of a magnetomotive force of the permanent magnet. The electromagnetic brake is released.

The magnetic fluid applied to the present invention is a colloidal fluid in which ferromagnetic powder (for example, fine particles of about 10 nm) is stably dispersed in a solution (for example, an organic solvent). Although it is in a solid state or in a fixed state, even if a shear force exceeding the allowable level acts, only the chains of the fluids are separated, and the magnetic powder itself is not affected.

Since the present invention is configured as described above, the magnetic fluid generates a resistance against shearing by a certain chain under a certain magnetic field, and generates a certain resistance even after being sheared. Since the drag at this time is larger than the braking frictional force, the entire electromagnetic brake can be reduced in size. Further, the drag can be easily adjusted by the strength of the magnetic field, and since no armature, which is a conventional movable portion, is required, no sound is generated during braking.

In the non-excitation operation type electromagnetic brake of the present invention,
When a direct current is applied to the coil winding and the electromagnetic brake body is excited to release the brake, a small magnetic field is left in the magnetic circuit to prevent the magnetic fluid from leaking outside. Adjust the magnetic field strength beforehand. In this case, the action of the magnetic fluid by the remaining minute magnetic field is not applied to the load on the rotating shaft during rotation. If the action of the magnetic fluid due to the remaining minute magnetic field cannot be ignored as a load on the rotating shaft during rotation, a coating for preventing leakage of the magnetic fluid is applied to reduce the minute magnetic field to zero. To

Since there is basically no air gap in the magnetic circuit of the non-excited operation type electromagnetic brake, the magnetic resistance can be reduced and the magnetic design can be simplified. Further, compared to the conventional one, there are no movable parts such as a return spring and an armature, so that the structure can be simplified and the number of parts is reduced. In addition,
The non-excited operation type electromagnetic brake is not limited to a rotating shaft in principle, but can be realized by a linear motion mechanism due to its structure.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the drawings. First Embodiment FIG. 1 is a sectional view of an upper half showing a first embodiment of a non-excited operation type electromagnetic brake according to the present invention.

In FIG. 1, a non-excited operation type electromagnetic brake 11 is fixed to a rotor output shaft 4 of a motor 3 by a screw member, and is a brake circle as a brake movable portion integrally forming a disk made of a magnetic material. Plate 12 and coil winding 16
The electromagnetic brake main body 15 includes a yoke member 17 having a concentric cross section and a double annular shape (not limited to an annular shape, but a horseshoe shape), and the double annular yoke member 17. Two annular permanent magnets 18a, 18b opposed to each other and whose magnetic pole directions are opposite to each other in the axial direction of the rotating shaft 4 and concentrically fixed to the brake disk 12 side as the brake movable portion; Magnetic fluids 19a, 19b interposed or filled between the contact surfaces of the double annular yoke member 17 and each of the annular permanent magnets 18a, 18b.
It is composed of

When the coil winding 16 is not energized, the magnetic flux emitted from the permanent magnet 18a is transferred from the magnetic fluid 19a to the yoke 17a.
→ Magnetic fluid 19b → Permanent magnet 18b → Brake disk 12
, A magnetic circuit is formed again into the permanent magnet 18a. As long as the magnetic circuit is formed and the magnetic fluids 19a and 19b are located between the freely rotatable portion and the portion where the rotation is restricted, the permanent magnets 18a and 18b can be arranged at any position in the magnetic circuit. Good.

As described above, when the coil winding 16 is not excited, the magnetic fluids 19a and 19b are
a, 18b, and is solidified by the magnetic flux of the yoke member 1
7 and the permanent magnets 19a and 19b are fixed, and the output rotary shaft 4 of the motor 3 fixed to the brake disk 12 is restrained in the rotation direction, that is, the brake is applied. The rotating shaft 4 is provided with the permanent magnets 18a, 18b.
Of the magnetic fluids 19a and 19b caused by the shear force of the magnetic fluids 19a and 19b.

Next, a direct current is supplied to the coil winding 16 to make it excited, and the direction of the magnetic force in the electromagnetic brake body 15 is made to act in a direction opposite to the direction of the magnetomotive force of the permanent magnets 18a, 18b. The magnetic flux passing through the magnetic fluids 19a and 19b is reduced, that is, the strength of the magnetic field is reduced to release the solidification of the magnetic fluids 19a and 19b and release the electromagnetic brake.

In this way, the electromagnetic brake 11 releases the restraint (brake) only when the coil winding 16 is energized, and restrains the rotary shaft 4 when not energized. The brake 11 can be obtained. The above is the embodiment of the non-excitation operation type electromagnetic brake fixed to the rotating shaft 4 of the motor 3, but the mechanism is not limited to the motor 3 as long as the mechanism has a freely rotating shaft.

FIG. 2 is a sectional view of an upper half showing another example of the non-excited operation type electromagnetic brake of the first embodiment.
The non-excited operation type electromagnetic brake 21 shown in FIG. 2 is different from FIG. 1 in that the cross section of the electromagnetic brake main body 25 is opposed to the double annular yoke member 27 and the magnetic pole direction is the same as the axial direction. In this example, the two annular permanent magnets 18a and 18b are fixed so as to be embedded in the respective portions on the yoke member 27 side in the opposite direction. The magnetic fluids 19a, 19b are interposed or filled between the two annular permanent magnets 18a, 18b on the side of the electromagnetic brake main body 25 and the abutting surface of the brake disk 12. The respective operations at the time of non-excitation and excitation of the non-excitation operation type electromagnetic brake 21 are the same as those of the first embodiment.

FIG. 3 is a sectional view of an upper half showing still another example of the non-excited operation type electromagnetic brake of the first embodiment. The non-excitation type electromagnetic brake 31 shown in FIG. 3 is different from FIG. 2 in that the two annular permanent magnets 18a and 18b are provided.
Of these, in the example in which a slight gap 32 is formed between the contact surfaces between the inner permanent magnet 18a and the brake disk 12, the magnetic fluid 19 is formed in a portion where the gap 32 is formed.
a is not intervened or filled. The operation of the non-excitation operation type electromagnetic brake 31 at the time of non-excitation and excitation is the same as that of the first embodiment. In this case, the air gap 32 exists in the magnetic circuit in the electromagnetic brake body 15,
Although the efficiency is reduced, there is an advantage that the amount of the magnetic fluid to be used can be reduced.

[Second Embodiment] FIG. 4 is a sectional view showing a non-excitation type electromagnetic brake according to a second embodiment of the present invention, which is applied to a linear motion mechanism.

In FIG. 4, the non-excited operation type electromagnetic brake 41 is made of a magnetic material and has guide members 42a, 42 on both sides.
2a, an electromagnetic brake main body 45 including magnetic material yoke members 47a and 47b having coil windings 46 mounted below a carriage 43 made of a non-magnetic material; In the magnetic circuit formed by the bottom portion 42b of the guide rail 42 and the permanent magnet 48 wound around the coil winding 46 and having a magnetic pole direction in the axial direction (left-right direction in the figure), The bogie 43 to which 45 is attached is disposed on the guide rails 42a, 42a via rollers 44, so as to run freely.

The two yoke members 47a and 47b are
One end of each of the yoke members 47a, 47b is disposed opposite to the bottom 42b of the guide rail 42. Then, the two yoke members 47
a, 47b between the surface of the guide rail 42 facing the bottom 42b and the bottom 42b.
a, 49b are interposed or filled.

When the coil winding 46 is not energized, the magnetic flux emitted from the permanent magnet 48 is applied to the yoke member 47a → the magnetic fluid 4
9a → bottom 42b of guide rail 42 → magnetic fluid 49b
A magnetic circuit is formed along the path from the yoke member 47b to the permanent magnet 48. As described above, when the coil winding 46 is not excited, the magnetic fluids 49a and 49b are solidified by the magnetic flux of the permanent magnet 48, and the yoke members 47a and 47b are solidified.
And the bottom 42b of the guide rail 42 is fixed, and the carriage 43 is restrained by the guide rail 42, that is, the brake is applied. The carriage 43 is restrained and held in the linear motion direction by the shearing force of the magnetic fluids 49a and 49b generated by the permanent magnet 48.

Next, the coil winding 46 is excited,
The magnetic fluid 49a, 4 is acted on in a direction opposite to the direction of the magnetomotive force of the permanent magnet 48 in the electromagnetic brake main body 15.
The magnetic flux passing through 9b is reduced, that is, the strength of the magnetic field is reduced, and the solidification of the magnetic fluids 49a and 49b is released to make them fluid, and the electromagnetic brake is released. For this reason, the carriage 43 is provided with the guide portions 42a, 4 of the guide rail 42.
The vehicle can freely travel on the roller 2a via the rollers 44,44.

Note that the technology of the present invention is not limited to the technology in the above-described embodiment, but may be implemented by means of other modes that perform the same function. Various changes and additions are possible.

[0033]

As is apparent from the above description, according to the non-excited operation type electromagnetic brake of the present invention, the brake movable member made of a magnetic material fixed to the rotating shaft and the yoke member having the coil winding are used. An electromagnetic brake comprising: an electromagnetic brake main body; and a permanent magnet disposed in a magnetic circuit formed by the electromagnetic brake main body and the brake movable member. With magnetic fluid interposed or filled in between,
The magnetic force direction in the excited state of the electromagnetic brake body,
Since the electromagnetic brake is released by acting in the direction opposite to the direction of the magnetomotive force of the permanent magnet, wear of the braking portion can be eliminated, and its life can be extended, and noise generated from the braking portion can be eliminated. .

Further, according to the present invention, when braking, there is an effect that the movable part is eliminated structurally and the structure becomes simple, and the number of components can be reduced.

Furthermore, according to the present invention, a guide rail made of a magnetic material, an electromagnetic brake main body made of a yoke member having a coil winding attached to a bogie made of a non-magnetic material, the electromagnetic brake main body and the guide And a permanent magnet disposed on the electromagnetic brake main body in a magnetic circuit formed by a rail, and the bogie to which the electromagnetic brake main body is attached is movably disposed on the guide rail via rollers. An electromagnetic brake, wherein a magnetic fluid is interposed between the electromagnetic brake main body and the guide rail, and a magnetic force direction in an excited state of the electromagnetic brake main body is opposite to a direction of a magnetomotive force of the permanent magnet. To release the electromagnetic brake, thereby eliminating wear of the braking portion, extending its life, and It is possible to eliminate the sound generated. Further, according to the present invention, there is an effect that, during braking, a simple structure is obtained by eliminating a movable portion, and the number of components can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an upper half showing a first embodiment of a non-excited operation type electromagnetic brake of the present invention.

FIG. 2 is a sectional view of an upper half showing another example of the non-excitation operation type electromagnetic brake of the first embodiment.

FIG. 3 is a cross-sectional view of an upper half showing still another example of the non-excitation operation type electromagnetic brake of the first embodiment.

FIG. 4 is a sectional view showing a second embodiment of the non-excited operation type electromagnetic brake according to the present invention, which is applied to a linear motion mechanism.

FIG. 5 is a cross-sectional view of an upper half showing a conventional non-excited operation type electromagnetic brake.

[Explanation of symbols]

1,11,21,31,41 Electromagnetic brake (non-excitation operation type electromagnetic brake) 2,12 Brake disk (brake movable part) 3 Motor 4 Rotary shaft 5,15,25,45 Electromagnetic brake main body 6,16,46 Coil winding 7, 17, 27, 47a, 47b Yoke member 8 Armature 8a Brake lining 18a, 18b, 48 Permanent magnet 19a, 19b, 49a, 49b Magnetic fluid 32 Air gap 42 Guide rail 42a Guide portion 42b Bottom 43 Bogie 44 Roller

Claims (5)

[Claims] 1. A brake movable member made of a magnetic material and fixed to a rotating shaft, an electromagnetic brake body made of a yoke member having a coil winding, and a magnet formed by the electromagnetic brake body and the brake movable member. An electromagnetic brake comprising a permanent magnet disposed in a circuit, wherein a magnetic fluid is interposed or filled between the electromagnetic brake main body and the brake movable member, and a magnetic force direction in an excited state of the electromagnetic brake main body. In the direction opposite to the direction of the magnetomotive force of the permanent magnet to release the electromagnetic brake. 2. The non-excited operation type electromagnetic brake according to claim 1, wherein the permanent magnet is disposed on the brake movable member side. 3. The non-excited operation type electromagnetic brake according to claim 1, wherein the permanent magnet is disposed on the electromagnetic brake main body side. 4. The non-excited operation type electromagnetic brake according to claim 1, wherein a gap is formed in a part between the electromagnetic brake main body and the brake movable member, which is filled with the magnetic fluid. . 5. An electromagnetic brake main body comprising a yoke member having a coil winding attached to a carriage made of a non-magnetic material, a guide rail made of a magnetic material, and the electromagnetic brake main body and the guide rail. And a permanent magnet disposed on the electromagnetic brake body in a magnetic circuit,
The bogie to which the electromagnetic brake main body is attached is an electromagnetic brake that is movably disposed on the guide rail via a roller, wherein a magnetic fluid is interposed between the electromagnetic brake main body and the guide rail. A non-excitation actuated electromagnetic brake, wherein the direction of the magnetic force in the excited state of the electromagnetic brake main body acts in a direction opposite to the direction of the magnetomotive force of the permanent magnet to release the electromagnetic brake.