JPH08266009A - Permanent magnet type non-excitation operation magnetic brake - Google Patents

Abstract

PURPOSE: To improve the defect of a high manufacturing cost caused by complicated armature fitting structure to a hub, a large number of parts needed, troublesome fitting work, etc., by preventing a quick responding permanent magnet type non-excitation operation magnetic brake from chattering at the time of being driven by a power source with a high ripple ratio. CONSTITUTION: A hub 3 fixed on the periphery of the rotational shaft 42 of a motor 4, an armature assembly 1 caulked to this hub 3, unable to move in the axial direction, and rotatable, and a magnet assembly 2 supported with holding bolts 21 by the stationary part 41 of the motor, and movable in the axial direction by receiving the elastic force of coil springs 23 provided in the peripheries of these holding bolts 21, are provided. And the armature assembly 1 and the magnet assembly 2 are attracted by the attracting force of the permanent magnet 11 of the armature assembly 1. And apart from that, the hub and the armature assembly are fixed with screws, or leaf springs are inserted between the magnet assembly and the stationary part in place of the coil springs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type non-excitation electromagnetic brake attached to a rotary shaft of a motor or the like to intermittently maintain a braking or driving state, and particularly to prevent chatter noise from occurring. The present invention relates to a release structure of a permanent magnet type non-excitation actuated brake that reduces manufacturing cost without lowering performance.

[0002]

2. Description of the Related Art FIG. 7 is a half sectional side view showing the structure of a typical example of a permanent magnet type non-excitation actuated electromagnetic brake according to the prior art. Reference numeral 70 denotes a permanent magnet type non-excitation actuated electromagnetic brake, which includes a magnet assembly 2 arranged on the outer peripheral side of the rotation shaft 42 of the motor 4 and an armature arranged axially opposite the magnet assembly 2. An assembly 60,
The armature assembly 60 is supported by a leaf spring 67 and is constituted by a hub 65 fixed to the rotary shaft 42 of the motor 4. The magnet assembly 2 is attached to the fixing portion 41 of the motor 4 with the magnet assembly fixing bolts 43, is made of a magnetic material and has a built-in electromagnetic coil 24 that is energized and excited via the lead wire 26, and is a double cylinder with a bottom. The yoke 27 and a facing 28 made of a non-magnetic material and fixed to the open end side of the yoke 27. The armature assembly 60 is arranged so as to face the fixed portion 41 of the magnet assembly 2 on the axially opposite side with a predetermined gap a in the non-excited state, for example, with a ring-shaped permanent magnet 11. The magnetic gap 12 is provided, and the surface opposite to the facing surface is axially movable via the leaf spring 67 in the axial direction as indicated by the arrow A by means of two kinds of screws 66 and 13 on the hub 65. It is fixed. On the outer peripheral surface of the rotating shaft 42 of the motor 4 on the tip side, for example, a D-cut portion 44 is formed.
Is formed, and the inner peripheral side of the hub 65 is formed into a shape that is substantially the same as the cross-sectional shape of the D-cut rotating shaft 42, into which the hub 65 is fitted. It is also fixed in the axial direction, and the rotary shaft 42
The hub 65 and the armature assembly 60 are rotated or braked in the rotational direction as an integrated structure.

The operation of the permanent magnet type non-excitation actuating electromagnetic brake 70 attached to the motor 4 will be described. In the non-excitation state in which the electromagnetic coil 24 is de-energized, the armature assembly 60 and the yoke 27 recirculate. Due to the magnetic flux Φ of the magnet 11, the armature core 14 made of a magnetic material causes the leaf spring 6 to move.
7 is attracted to the yoke 27 made of the magnetic material of the fixed magnet assembly 2 against the elastic force of the both assemblies 60,
The two opposing surfaces are attracted to each other and the rotation is braked by the friction between the facing 28 and the armature assembly 60, the rotation of the rotary shaft 42 is braked via the hub 65, and the motor 4 is stopped. On the other hand, when the electromagnetic coil 24 is energized,
This electromagnetic coil 24 generates a magnetic flux whose direction is opposite to that of the magnetic flux Φ generated by the permanent magnet 11, cancels the magnetic flux Φ generated by the permanent magnet 11, and the attractive force between the two assemblies 60, 2 disappears.
The armature assembly 60 and the magnet assembly 2 are separated by applying the elastic force of 7, and the rotating shaft 42 fixed to the armature assembly 60 and the hub 65 is released from braking and becomes rotatable. The permanent magnet type non-excitation actuated electromagnetic brake is recommended to use a DC smoothing or purely stabilized stabilizing power supply as the power supply, and the time constant of the inductance (delay of the rise of the magnetic flux) is extremely small, so energize it. Immediately after disconnection, the armature assembly starts the suction operation, and particularly in the earlier case, the suction operation starts after 2-3 msec. Such good response is the greatest feature of the permanent magnet type non-excitation actuated electromagnetic brake.

[0004]

On the other hand, if a rectified full-wave or half-wave power source of a general unstable [high ripple (pulsation) rate] power supply device is used as a power source for a permanent magnet type non-excitation actuated electromagnetic brake, In a part of the operating voltage range, when the electromagnetic coil is de-energized (when the brake is released), the leaf spring that pulls back the armature assembly that has a small mass and is movable in the axial direction to the hub side causes chatter vibration. In some cases, it becomes a sound and a noise is generated. One of the problems to be solved by the present invention is to prevent the use member from being worn out or suffering from poor insulation due to the above-mentioned vibration, and at the same time to prevent the generation of unpleasant noise. In addition, the permanent magnet type non-excitation actuated electromagnetic brake with the above-mentioned structure has a structure in which the armature assembly is fixed to the hub with screws through a leaf spring, so the structure is complicated and the number of parts is large, and the periphery of the mounting part is However, it has a drawback that the manufacturing cost is high because the installation work with screws is troublesome due to its narrow size. The present invention has made it a problem to be solved to develop a permanent magnet type non-excitation actuated electromagnetic brake which eliminates the above-mentioned two drawbacks, does not generate vibration and noise, and further reduces the manufacturing cost.

[0005]

The chattering vibration at the time of releasing the brake is such that the time constant of the inductance is extremely small, the elastic force of the leaf spring is large, and the armature assembly having a small mass is moved in the axial direction. Therefore, since the leaf spring resonates with the ripple of the power frequency, attention is paid to the elastic force of the spring and the mass of the moving member, and countermeasures are taken to prevent chatter vibration. Also, the number of assembly steps and the number of parts on the armature assembly side will be reduced to reduce the manufacturing cost. Therefore, the present invention has solved the problem by a permanent magnet type non-excitation actuated electromagnetic brake adopting the following means. 1) Contrary to the conventional method, the armature assembly is made immovable in the axial direction, and a magnet assembly with a large mass is built in to move the magnet assembly in the axial direction when braking and releasing the brake. A coil spring (relief coil spring) is provided on the holding bolt that attaches the magnet assembly to the fixed part of the motor as a spring means to replace the leaf spring as a drive source that separates the armature assembly and the magnet assembly at the time of release to prevent chatter vibration. 3) To prevent the generation of vibrations and noise due to the collision between the magnet assembly and the fixed part, attach a plastic film to the collision surface of the fixed part. 4) Attach the armature assembly directly to the hub. Fixing with screws or caulking eliminates the need for two types of screws that were attached to conventional leaf springs. And reduced manufacturing costs by reducing the assembling steps as well as simplify Jo.

[0006]

In the permanent magnet type non-excitation actuated electromagnetic brake of the present invention having the above structure, the magnet assembly having a large mass is used as the moving member, and the coil spring having a small elastic force (spring constant) is used. The movement in the axial direction becomes slower, and resonance due to ripples in the power supply frequency is eliminated to prevent chatter noise. Furthermore, since the armature assembly is immovable in the axial direction, it can be directly attached to the hub by caulking, and members such as screws and screwing work are unnecessary, simplifying the shape of the armature core and processing cost. Manufacturing cost by reducing the size of the hub and reducing the material cost.

[0007]

1 is a half-body sectional side view showing a first embodiment of a permanent magnet type non-excitation actuated electromagnetic brake of the present invention. In the following description, description of the same members as those already described as the conventional technique will be omitted. The hub 3 of the permanent magnet type non-excitation actuated electromagnetic brake of the present embodiment is engaged with the outer peripheral side of the rotary shaft 42 in the same manner as the conventional technique, but the outer peripheral side of the hub 3 has the leaf spring 67 of the conventional technique. Since it is not necessary to attach (see FIG. 7), the dimension in the radial direction is smaller than that of the conventional one. Since the armature assembly 1 is caulked and directly fixed to the outer peripheral side of the hub 3 in this example,
In the armature core 5 of this armature assembly 1,
Neither the screw hole of the screw 13 for attaching the leaf spring 67 of the prior art nor the hole for inserting the screw 66 for fixing the hub 65 (see FIG. 7) is required, and the shape is simpler than the conventional one. In the present invention, since the armature assembly 1 is fixed in the axial direction so as not to move, the magnet assembly 2 is used.
Was arranged so as to be movable in the axial direction. That is, the magnet assembly 2 having the same structure as that of the conventional technique is attached to the fixing portion 41 of the motor 4 by the magnet assembly holding bolt 21 (hereinafter abbreviated as holding bolt).
A coil spring 23 is provided on the outer periphery of the holding bolt 21 between the head portion 21a of the magnet assembly 21 and the flange portion 22 of the magnet assembly 2, and the magnet assembly 2 is attached so as to be movable in the axial direction as indicated by arrow B. .

The operation of the permanent magnet type non-excitation operated electromagnetic brake 10 of this embodiment will be described. When the armature assembly 1 attracts the magnet assembly 2, unlike the conventional art, the magnet assembly 2 moves in the axial direction against the elastic force of the coil spring 23. As a result, the following remarkable effects are obtained. Present. B) The magnet assembly 2 which is larger and has a larger mass than the armature assembly incorporating the electromagnetic coil 24 is moved in the axial direction to perform braking and releasing operations of the brake, and, as will be described later, an elastic load for flexure. Since the small coil spring 23 is used, the return of the magnet assembly 2 to the fixed portion 41 side when the brake is released becomes slower than in the conventional case, and the occurrence of chatter vibration is suppressed. (B) Since the armature assembly 1 and the hub 3 are integrally formed, two types of screws 6 for fixing via the conventional leaf spring 67 are provided.
6 and 13 are unnecessary, assembly work with low workability by these screws 66 and 13 (see FIG. 7) is unnecessary, the shape of the armature core 5 is simplified, and the size of the hub 3 is reduced to reduce the manufacturing cost. Contributed to the reduction of Further, the permanent magnet type non-excitation actuated electromagnetic brake 10 of the present embodiment is also effective for increasing the degree of freedom in design and assembly work for the following reason. C) Fig. 2 is a schematic diagram showing a comparison of the change in elastic load with respect to the amount of deflection of the coil spring and the leaf spring. The amount of change in load with respect to the constant amount of deflection of the coil spring is smaller than in the case of the leaf spring. Therefore, it is shown that the coil spring can be used with a spring load in a predetermined range in a wider deflection range than the leaf spring. That is, in FIG. 1, the coil spring 23 has a stable suction operation in a wide range of the distance between the facing surfaces of the armature assembly 1 and the magnet assembly 2, and therefore, the dimension setting at the time of design and the dimension adjustment at the time of assembly are easy. To Further, compared to the case where the conventional leaf spring 67 (see FIG. 7) is used, both the assemblies 1 and 2 can be attracted even if the interval between the facing surfaces is increased to 1.5 to 2 times. Is.

FIG. 3A is a half sectional side view showing the mounting structure of the magnet assembly 2 of the second embodiment of the permanent magnet type non-excitation actuated electromagnetic brake of the present invention, and FIG. ,
It is the front view which looked at the leaf spring 25 of the figure (A) from the axial direction. The present embodiment differs from the first embodiment only in that the magnet assembly 2 is attached to the fixing portion 41 via the leaf spring 25, but the assembly is facilitated and the number of parts is reduced. Manufacturing costs are reduced, and chatter vibration is suppressed because the magnet assembly 2 is movable in the axial direction. This is similar to the first embodiment in that it solves the problems of the present invention. . FIG. 4 is a half sectional side view showing an armature assembly 50 of a third embodiment of the permanent magnet type non-excitation actuated electromagnetic brake of the present invention. The present embodiment is different from the first or second embodiment described above in that the armature assembly 50 is attached to the hub 52 by the screw 51, and has substantially the same effect as these embodiments. There is. FIG. 5 shows an armature assembly 55 and a hub 56 of a fourth embodiment of the permanent magnet type non-excitation actuated electromagnetic brake of the present invention. FIG. 5 (A) is a half body side view, and FIG. B) is a front view. The armature assembly 55 of this embodiment is formed integrally with a hub 56 made of a mold resin by insert molding or the like. Further, in each of the above-described embodiments, the vibration or sound generated by the collision of the fixed portion 41 when the magnet assembly 2 is returned can be eliminated by previously attaching an adhesive sheet of a plastic material to the collision surface of the fixed portion 41. Is. FIG. 6 is a half sectional side view of a fifth embodiment of the permanent magnet type non-excitation actuated electromagnetic brake of the present invention with a part thereof cut away. The armature assembly 55a of this embodiment is integrally formed with the hub and is fixed to the rotary shaft 42. Further, the facing of the magnet assembly 2a is removed, and when the electromagnetic coil 24 is in the non-excited state, the armature assembly 55a and the yoke are formed. Only 27a abuts to brake the rotation of a motor (not shown). As described above, by integrating the armature assembly and the hub and removing the facing, the material cost and the processing cost are reduced and the manufacturing cost is reduced as compared with the conventional case.

[0010]

The permanent magnet type non-excitation actuated type electromagnetic brake of the present invention axially moves the larger magnet assembly having the larger mass at the time of braking or releasing the brake, and the coil spring having a small elastic force at the time of releasing the braking. With the use of, the production of chattering noise is prevented, the number of parts is reduced, the shape of the armature core is simplified, and the hub is downsized.

[Brief description of drawings]

FIG. 1 is a half-body sectional side view showing a first embodiment of a permanent magnet type non-excitation operated electromagnetic brake of the present invention.

FIG. 2 is a schematic diagram showing a comparison of a change in elastic load with respect to a deflection amount of a coil spring and a leaf spring.

FIG. 3A is a half-body side view showing a mounting structure of a magnet assembly of a second embodiment of a permanent magnet type non-excitation operated electromagnetic brake of the present invention, and FIG. 8A is a front view of the leaf spring shown in FIG.

FIG. 4 is a half-body sectional side view showing an armature assembly of a third embodiment of a permanent magnet type non-excitation actuated electromagnetic brake of the present invention.

FIG. 5 is a view showing an armature assembly and a hub of a fourth embodiment of a permanent magnet type non-excitation actuated electromagnetic brake of the present invention,
(A) of this figure is a half-body cross-sectional side view, and (B) of this figure is a front view.

FIG. 6 is a half-body sectional side view showing a fifth embodiment of a permanent magnet type non-excitation actuated electromagnetic brake of the present invention with a part thereof broken away.

FIG. 7 is a half-body sectional side view showing the structure of a typical permanent magnet type non-excitation actuated electromagnetic brake according to the prior art.

[Explanation of symbols]

 1, 50, 55, 55a Armature assembly 2 Magnet assembly 3, 52, 56 Hub 4 Motor 10 Permanent magnet type non-excitation actuated electromagnetic brake 11 Permanent magnet 12 Magnetic gap 21 Magnet assembly holding bolt 21a Head 21b Body part 22 Flange 23 Coil spring 24 Electromagnetic coil 25 Leaf spring 27 Yoke 28 Facing 41 Fixed part 42 Rotating shaft 51 Screw

Claims (5)

[Claims] 1. An annular armature assembly (1) having a permanent magnet (11) and a magnetic air gap (12), and a bottomed double cylindrical yoke (2) containing an electromagnetic coil (24).
7) and a facing (28) fixed to the open end of the yoke (27), which cannot rotate, and a non-rotatable magnet assembly (2) which engages with the outer peripheral side of the rotating shaft (42) of the motor (4). And a hub (3) for rotatably holding the armature assembly (1) integrally with the rotating shaft (42), the rotor being rotated by the magnetic force of the permanent magnet (11) in a non-excited state. The armature assembly (1) arranged on the outer peripheral side of the shaft (42) and the axially opposite surfaces of the magnet assembly (2) are attracted to each other, and are rotated by frictional force via the hub (3). The shaft (42) is braked, and the electromagnetic coil (2
When 4) is energized and excited, the magnetic force of the permanent magnet (11) is canceled out by the spring means having an elastic force in the axial direction,
In a permanent magnet type non-excitation actuated electromagnetic brake (10) in which the armature assembly (1) and the magnet assembly (2) are separated to release braking: The armature assembly (1) is fixed to the hub (3) The magnet assembly (2) has its flange portion (22) held by the magnet assembly holding bolt (21) on the fixing portion (41) of the motor (4) and is spring-loaded. A coil spring (2) provided on the outer periphery of the body portion (21b) between the head portion (21a) of the magnet assembly holding bolt (21) and the flange portion (22) as means.
The permanent magnet type non-excitation is characterized in that it is movable in the axial direction by receiving the elastic force of 3), and chatter vibration due to resonance is reduced even when the electromagnetic coil (24) is energized from an unstable power source. Actuated electromagnetic brake. 2. A permanent magnet type non-excitation actuated electromagnetic brake according to claim 1, wherein said armature assembly (1) is caulked and fixed to said hub (3). 3. The armature assembly (50) has a screw (5).
The permanent magnet type non-excitation actuated electromagnetic brake according to claim 1, which is fixed to the hub (52) by 1). 4. The armature assembly (55) comprises a hub (5).
6) Integrally molded into 6) by insert molding or the like
The permanent magnet type non-excitation actuated electromagnetic brake described. 5. A permanent magnet type non-excitation actuated electromagnetic brake according to claim 1, wherein a leaf spring (25) as spring means is provided between the magnet assembly (2) and the fixed portion (41). .