JP2016171727A - Eddy current braking apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic braking apparatus capable of performing braking operation of a brake in a non-contact state and capable of downsizing the apparatus.SOLUTION: In an eddy current braking apparatus, a first rotor which is a mechanism requiring torques of winding or unwinding operation etc. in a treatment step of films, fibers, etc. and includes a permanent magnet group for generating eddy current braking and a second rotor including a conductor disk on the surface are arranged through a desired interspace. By arranging a plurality of projections of magnetic materials on the conductor disk at an equal pitch, an eddy current braking amount to be generated in accordance with a relative rotational speed difference between the two rotors can be increased and the apparatus can be also downsized.SELECTED DRAWING: Figure 1

Description

The present invention relates to an eddy current brake for transmitting a predetermined torque to a rotating device by applying a load from a rotating machine such as an electric motor in a mechanism that requires torque such as winding or unwinding operation in a film processing process. In particular, the present invention relates to an eddy current brake device characterized in that the braking force by eddy current can be greatly increased.
In addition, the present invention relates to a power transmission device having a rotating system, and relates to an eddy current braking device having a brake function in which the transmission force slips due to a load and has a built-in function of reducing the rotational speed. The present invention relates to an eddy current brake device in which the brake force can be adjusted and the brake force can be adjusted.

A conventional eddy current brake of this type has a large number of magnets with N.P. S A rotating body (or stationary body) alternately arranged on a disk has a stationary board (or rotating body) in which a conductor (for example, aluminum) is disposed so as to face each other, and a vortex corresponding to the number of rotations of the rotating body An eddy current brake appears by generating a current in a conductor. (See Patent Document 1.)

JP-A-6-014523

However, in the eddy current brake proposed in Patent Document 1 described above, the braking force caused by the eddy current generated according to the number of rotations of the rotating body is small, and therefore the shape is required to ensure the necessary braking force. There are drawbacks such as an increase in size. In order to compensate for this, it has been proposed to secure a braking force by using a plurality of opposing portions. In this case, however, the structure becomes complicated, and the rotating body and the fixed body are used to adjust the braking force. There is a defect that the adjustment of the voids cannot be performed easily.

In order to solve the above-described problems, an object of the present invention is to provide an eddy current brake device incorporating an eddy current brake method capable of obtaining a strong braking force.

In order to achieve the above object, according to claim 1 of the present invention, a first rotating body in which N poles and S poles are alternately arranged in a rotating direction on a side surface of a disk-shaped rotating body made of a magnetic body, A second rotating body composed of a magnetic disk having a predetermined gap and facing a magnet surface of one rotating body is opposed to each other in a non-contact manner, and a relative rotational speed between the two rotating bodies is set. In an eddy current brake device in which a braking force is generated between both rotating bodies by an eddy current generated according to the difference, a protrusion having a predetermined height is provided on a side surface of the magnetic disk of the second rotating body, and The eddy current brake device is characterized in that the conductor disk is embedded in a form to cover the protrusion.

In the eddy current device according to claim 2 of the present invention, the number of magnet poles of the first rotating body and the number of protrusions of the projecting portion of the second rotating body are different from each other in claim 1 described above. The problem is solved by the eddy current brake device according to claim 1.

Further, in claim 3, the conductive disk of the second rotating body can be easily replaced according to the magnitude of the specific resistance value, and the eddy current braking force can be easily adjusted. The problem is solved by the eddy current brake device according to claim 1 or 2.

Further, in claim 4, the eddy current brake device according to any one of claims 1 to 2, wherein either the first rotating body or the second rotating body is fixed. .

On the other hand, in Claim 5, the permanent magnet of the said 1st rotary body was made into the electromagnet, The eddy current brake apparatus of Claim 1 thru | or 2 characterized by the above-mentioned.

In the eddy current brake device of the present invention, it becomes possible to greatly improve the eddy current brake force acting between rotating bodies without providing a special mechanism in a limited shape and space. Contributes greatly to improved performance. Further, when used as an eddy current coupling, the setting torque of the eddy current coupling is widened by increasing the limit torque at which slip occurs, resulting in the effect of expanding the application range and use of products. Furthermore, different conductor discs such as the specific resistance values of the conductor discs that are closely related to the eddy current brake characteristics (for example, copper plates, 1000 type aluminum plates, 5000 type aluminum plates) are selected as appropriate, and the product It is possible to easily replace with screws etc. according to the demands of the limit torque and brake amount, and as a result, setting of brake force and transmission torque characteristics can be done without making a complicated mechanical structure of adjusting the gap between rotating bodies. An easy and inexpensive eddy current brake device can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a general view of the eddy current brake device which is embodiment of this invention, A is the side view, B is sectional drawing of a side. The front view of the 1st rotary body shown in FIG. The front view of the 2nd rotary body shown in FIG. Sectional drawing of the side surface of the 2nd rotary body based on a prior art example. The front view of the 2nd rotary body based on a prior art example. It is explanatory drawing which shows the flow of the magnetic flux which generate | occur | produces between the rotary body 1 and the rotary body 2, A is a structure of this invention, B shows the conventional general structure. It is a graph which shows the torque characteristic which generate | occur | produces by the brake effect | action with respect to the relative rotational speed difference of the 1st rotary body of a eddy current brake, and a 2nd rotary body. In another embodiment of the present invention, A is a front view of the first rotating body, and B is a sectional view thereof.

Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1A is a side view of an eddy current brake device according to an embodiment of the present invention, and FIG. 1B is a side sectional view thereof. In the figure, reference numeral 1 denotes a first rotating body, which is composed of a magnetic disk 10 of magnetic material, a permanent magnet group 11 and a first central shaft 12. The magnetic disk 10 is provided with a shaft hole 10a in the center, and the first center shaft 12 passes through the shaft hole 10a and is fixed to the magnetic disk 10 by a parallel key 13 in a rotating state. On the other hand, reference numeral 2 denotes a second rotating body 2, which is composed of a magnetic disk 20 made of a magnetic material having a shaft hole 20 b in the center and a conductive disk 21 in which an eddy current brake appears, and the surface of the magnetic disk 20. Is provided with a plurality of protrusions 20a shown in FIG. 3, and the conductor disk 21 provided with holes having substantially the same shape as the protrusions 20a in a manner sandwiching the periphery of the protrusions 20a is a screw or the like (not shown). The magnetic disk 20 is fixed so that the surface thereof is substantially the same as the protrusion 20a of the magnetic disk. Further, the second central shaft 22 passes through the through hole 20 b of the magnetic disk 20, and is fixed to the magnetic disk 20 with the shaft 22 by a parallel key 23.

FIG. 2 is a front view of the rotating body 1 described above. On the surface of the magnetic disk 10, a permanent magnet 11 a (surface is N pole) and a permanent magnet 11 b (surface is S pole) are provided at the center of the magnetic disk 10. A state is shown in which the shaft holes 10a are alternately disposed with an adhesive or the like at regular intervals in the rotation direction.

FIG. 3 is a front view of the second rotating body described above. The protrusions 20a... Provided on the magnetic disk 20 are provided at equal intervals in the rotational direction with respect to the central shaft 22, as described above. The conductor disk 21 provided with a hole having substantially the same shape as the protrusion 20a in a manner sandwiching the periphery of the protrusion 20a is inserted into the magnetic disk 20.

In this manner, the permanent magnet group 11 of the first rotating body 1 is arranged with a predetermined gap in such a manner that the conductor disk 21 of the second rotating body and the surface of the protrusion 20a face each other. Depending on the rotational speed difference between the two rotating bodies, the magnetic flux of the permanent magnet 11 becomes a flow of magnetic flux concentrated on the protrusion 20a of the second rotating body, and an eddy current is generated in the conductor disk 21 so as to cancel the magnetic flux. By acting, it acts as an eddy current brake between the first rotating body and the second rotating body.

4 and 5 show a second rotating body 3 of a conventional example in which the second rotating body 2 is configured based on a general conventional example. FIG. 4 is a sectional view of the side surface, and FIG. 5 is a front view. is there. In the figure, reference numeral 3 denotes a conventional second rotating body, which is composed of a magnetic disk 30 and a conductive disk 31 fixed to the side surface of the magnetic disk 30 with, for example, an adhesive. In addition, the 1st rotary body 1 is the same as the rotary body demonstrated with the eddy current brake apparatus which concerns on this invention mentioned above. As shown in the drawing, the second rotating body 3 is arranged in a form facing the permanent magnet group 11 of the first rotating body 1 in the same manner as the second rotating body 2 according to the embodiment of the present invention described above. Although an eddy current brake is configured, the magnetic disk 30 has no protrusions, and the surface of the conductive disk 31 is a permanent part of the first rotating body 1 except for the second rotating body according to the present invention. Opposing to the magnet group 11, the magnetic flux of the permanent magnet group 11 forms a magnetic circuit with the adjacent permanent magnets in the permanent magnet group 11 via the conductor disk 31. However, the magnetic permeability of the conductor disk is significantly lower than that of the magnetic material, so that the concentration of the magnetic flux is weak, and the magnetic flux is divided into the gap between the two rotating bodies. As a result, the second rotating body according to the present invention described above is obtained. The eddy current flowing in the conductor disk 31 is less than the eddy current flowing in the conductor disk 21, and the eddy current braking force is weak.

This situation is illustrated in FIG. FIG. 6A shows the flow of magnetic flux of the first rotating body 1 and the second rotating body of the present invention, and FIG. 6B is a trial of a general conventional example. In FIG. 6A, as described above, the path of the magnetic flux from the surface of the permanent magnet 11 a (the tip is N pole) of the permanent magnet group 11 toward the protrusion 20 a of the magnetic disk 20 becomes dominant and passes through the inside of the magnetic disk 20. A magnetic circuit is formed from the adjacent protrusion 20a so as to return to the permanent magnet 11b (the tip is the S pole) of the permanent magnet group 11, and the conductor disk is vortexed so as to cancel it according to the change in the magnetic flux density. An electric current flows and the eddy current loss due to the eddy current becomes a braking force. As a result, a strong eddy current braking force corresponding to a relative rotational speed difference is generated in the two rotating systems. FIG. 6B shows the flow of magnetic flux in a general conventional example. Since there is no protrusion (tooth yoke) in the magnetic disk 30 as described above, the magnetic flux does not concentrate and the resulting eddy current also appears. Therefore, the eddy current braking force is small. Note that the gap gap1 and the gap gap2 shown in FIGS. 6A and 6B have the same distance.

FIG. 7 is a diagram comparing the eddy current brake characteristics (or transmission torque) between the embodiment of the present invention and the conventional example, where the horizontal axis is the relative rotational speed difference between the two rotating bodies, and the vertical axis. Is torque (the eddy current braking force is expressed as torque). As can be seen from the figure, the braking force (torque) with respect to the relative rotational speed difference is about twice as large in the case with the protrusion (tooth yoke) of the present invention as compared with the case without the protrusion in the conventional example. Although not particularly shown, from the results of various experiments, it is more desirable that the number of poles and the number of protrusions of the permanent magnet is larger.

FIG. 8 shows another embodiment of the present invention, in which the permanent magnet group 11 of the first rotating body shown in FIG. 1 is an electromagnet type, FIG. 8A is a front view thereof, and FIG. 8B is a side view thereof. It is sectional drawing. In the figure, reference numeral 4 denotes a magnetic disk, and coils 42a and 42b are arranged on the side thereof as 42a, 42b, 42a, 42b... At equal intervals in the axial rotation direction with respect to the center of the magnetic disk. It is fixed to the base 41. Although connection of the terminal of the coil is not shown, for example, nine coils 42a are connected in series, and both ends thereof are connected to the output side of the DC power source and a DC voltage is applied. Similarly, nine coils 42b are connected in series, and a DC voltage is applied to both ends thereof. The direction of the current flowing through the coil is set according to the polarity of the applied voltage to determine the polarity of the coil surfaces of the coils 42a and 42b. The magnetic poles on the surfaces of the coils 42a and 42b are, for example, N poles on the surface of the coil 42a. Further, the surface of the coil 42b is excited to have a polarity different from that of the south pole, and the function of the eddy current brake is exhibited by fulfilling the roles of the north pole and south pole of the permanent magnet shown in FIG. In the figure, no magnetic material is provided at the center of each coil, but if necessary, an appropriate magnetic material can be provided to increase the magnetic force of the magnetic poles.

As described above, in the embodiment of the present invention, each rotating body of the permanent magnet board and the conductor board that generates the eddy current is a disk type, but the advantages of the disk type compared to the case where it is a cylindrical type are two opposing ones. By adjusting and setting the gap between the rotating bodies, the desired eddy current braking force can be easily obtained according to the relative rotational speed difference between the two rotating bodies. There is an advantage that the force characteristic can be easily set by making it steep or gentle by changing the number of poles of the permanent magnet on the magnetic disk. For example, increasing the number of poles of the permanent magnet makes the braking characteristics of the rotational speed difference between the two rotating bodies and the eddy current braking force steep. Accordingly, the gap between the two rotating bodies can be put to practical use as an eddy current clutch by separating the gap between the two rotators at a distance where the eddy current brake does not act.

As described above, the electromagnetic brake device according to the present invention is provided in such a manner that the working surfaces between the two rotating bodies face each other in a non-contact manner with a desired gap, and the relative rotational speed of the working surfaces. Since a larger braking force can be obtained even in a space where the braking force corresponding to the difference is limited, for example, film, glass fiber, carbon fiber winding, unwinding alignment, bending removal, etc. are wide There is utility value.

DESCRIPTION OF SYMBOLS 1 1st rotary body 10 Magnetic disk 11 Permanent magnet group 12 Central axis 13 Key 2 2nd rotary body 20 Magnetic disk 20a Protrusion part (tooth yoke)
21 Conductor disk 22 Center axis 23 Key 3 Second rotating body 30 Magnetic disk 31 Conductor disk 4 Electromagnetic disk 40 Circuit board holder 41 Circuit board 42a Excitation coil 42b Excitation coil

Claims (5)

On the side surface of the disk-shaped rotator made of a magnetic material, there is a first rotator in which N poles and S poles are alternately arranged in the rotation direction, and a predetermined gap facing the magnet surface of the first rotator. A second rotating body made of a magnetic disk provided with a conductive disk is opposed to each other in a non-contact manner, and a braking force is generated between the two rotating bodies by an eddy current generated according to a relative rotational speed difference between the two rotating bodies. In the generated eddy current brake device, a protrusion having a predetermined height is provided on a side surface of the magnetic disk of the second rotating body, and the conductor disk is embedded in a form covering the protrusion. Eddy current brake device. 2. The eddy current brake device according to claim 1, wherein the number of magnet poles of the first rotating body is different from the number of protrusions of the protrusions of the second rotating body. 3. The eddy current braking force can be easily adjusted by easily replacing the conductive disk of the second rotating body in accordance with the magnitude of the specific resistance value. 3. Eddy current brake device. 4. The eddy current brake device according to claim 1, wherein one of the first rotating body and the second rotating body is fixed. 5. 5. The eddy current device according to claim 1, wherein the permanent magnet of the first rotating body is an electromagnet.