JPH0432509Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a direct-acting electromagnetic brake used for braking and holding various machines.

[Conventional technology]

This type of electromagnetic brake is configured to brake the rotating shaft by magnetically attracting a rotating member and a stationary member provided on the rotating shaft by applying a voltage to an excitation coil. ing. Therefore, if a failure occurs in the electrical system, braking of the rotating shaft becomes completely impossible.

By the way, even if a failure occurs in such an electrical system, braking of the rotating shaft may be required. It is conceivable to connect the member on the fixed side and the member on the fixed side using an emergency connecting piece.

[Problem that the invention attempts to solve]

However, in such a structure, since the emergency coupling piece must be attached with bolts, there is a problem in that it is not possible to perform quick emergency braking or to gradually release the braking. on the other hand,
In order to prevent disasters in lifting and transporting machinery such as cranes and conveyors, even if everything including the drive source stops due to a failure of the electrical system, the equipment is It was necessary to hold the object in place or to lower it gradually by its own weight.

Therefore, it is possible to use a negative acting electromagnetic brake, but this type of negative acting electromagnetic brake uses the elastic force of a compression coil spring as a braking means, and this elastic force is gradually reduced. impractical as it is difficult to reduce.

[Means for solving problems]

The present invention was devised in view of these circumstances, and provides an electromagnetic brake that enables quick emergency braking and gradually releases braking even when excitation is disabled. It is something to do. The electromagnetic brake according to the present invention includes an annular disk made of a magnetic material that is supported movably in the axial direction between the rotating disk and the field core and has an annular groove that covers the field core from one side in the axial direction, An introduction section for introducing pressurized fluid into a pressure chamber formed between the annular disk and the field core is provided.

[Effect]

In the present invention, when pressurized fluid is introduced into the pressure chamber, the annular disk moves toward the rotating disk and comes into pressure contact with the rotating disk, so that a frictional force is generated between the rotating disk and the annular disk.

〔Example〕

Hereinafter, the configuration and the like will be explained in detail with reference to embodiments shown in the drawings. Fig. 1 is a cross-sectional view showing the electromagnetic brake according to the present invention, Fig. 2 is a partial cross-sectional view of the upper half showing a state where voltage is applied to the excitation coil, and Fig. 3 is a pressurized fluid inside the pressure chamber of the electromagnetic brake. In these figures, the reference numeral 1 indicates an electromagnetic brake, which is connected to a drive source of lifting and transporting machinery, industrial robots, etc., or a nearby power system. is installed on. Reference numeral 2 denotes a rotating shaft, which projects outward from the housing 3 of the brake target device. A field core 4 is disposed coaxially with the rotating shaft 2, and in this embodiment, it is formed separately from the housing 3 and fitted onto the rotating shaft 2. The excitation coil 6 is attached to the outer surface of the housing 3 with a mounting bolt 5, and is provided in an annular groove opened outward in the axial direction. Here, the field core 4 can also be constructed by providing an annular groove directly in the housing 3 and loading the excitation coil 6 into this annular groove.
7 is the lead wire of the exciting coil 6, 8 is the exciting coil 6
It is an insulating resin that fixes the

Reference numeral 9 denotes an adjustment shim fitted into the stepped portion of the rotating shaft 2. Reference numeral 11 denotes a rotating disk made of a magnetic material that is mounted on the rotating shaft 2 facing the field core 4 on the outside in the axial direction of these members, and has a keyway 10 formed therein. This rotating disk 11
is shaped like a disk with a hub in the center,
It is connected to the rotating shaft 2 by a key 12 so as to rotate integrally with the rotating shaft 2, and is connected to a predetermined position on the rotating shaft 2 by the shim 9 and a nut 13 screwed onto the tip of the rotating shaft 2. has been adjusted to the position of Arc-shaped slits 11a are bored in the rotary disk 11 at equal intervals on the same circumference, and magnetically insulating material 14 is filled and fixed therein. Note that it is not necessary to fill the magnetism-interrupting material 14, and the magnetism-interrupting portion may be formed by a gap.

Reference numeral 21 denotes an annular disk made of a magnetic material, which is interposed between the rotary disk 11 and the field core 4 and is the main part of the present invention. This annular disk 21
is formed into an annular shape having an annular groove 21a that covers the field core 4 from one side in the axial direction, in other words, from the opposite side to the housing 3, and has an arc-shaped slit 21b at the bottom similar to the rotary disk 11. The magnetic insulation materials 22 are drilled at equal intervals on the circumference.
The filling is fixed. More specifically, the annular disk 21 is formed to have a U-shaped cross section, covers the inner and outer circumferential surfaces and one end surface of the field core 4, and forms an annular pressure chamber 23 between the annular disk 21 and the field core 4.

Reference numeral 24 denotes a leaf spring that supports the annular disk 21 so as to be movable in the axial direction while always biasing it away from the rotary disk 11.The base end is fixed to the housing 3 with a collar 25 and a bolt 26, and the distal end is fixed to the housing 3 with a collar 25 and a bolt 26. A bolt 27 is attached to an outer flange 21c protruding from the opening edge of the annular disk 21 in the outer radial direction.
It is fixed by the head and retaining ring 28. 29
is a locking plate as a locking means for locking the annular disk 21 from moving in the direction away from the rotary disk 11, and in this embodiment, it is fitted into the annular groove 4a on the inner circumferential surface of the field core 4. has been done.
Here, as the locking means, a member may be provided on the outer peripheral surface of the field core 4 that contacts the outer peripheral portion of the annular disk 21, or a structure may be adopted in which the head of the bolt 27 is brought into contact with the outer surface of the housing 3. In short, any structure that can provide the initial elastic force of the leaf spring 24 may be used. As the leaf spring 24, for example, one having an arc shape or a rectangular shape can be used, and various fixing means can be considered in addition to the above-mentioned bolts.

31 is a movable disk made of a magnetic material that faces the annular disk 21 via the rotating disk 11 and is supported on the bolt 27 so as to be movable in the axial direction coaxially with the rotating shaft 2. This movable disk 31 is a compression coil spring 33 interposed in a compressed and deformed state between a retaining ring 32 fitted to a bolt 27,
It is constantly biased in the direction away from the rotating disk 11, and movement in the direction away from the rotating disk 11 is stopped by an adjustment nut 34 and a lockite 35 screwed onto the tip of the bolt 27. . Here, in the non-excited state, the gap g ₁ between the rotating disk 11 and the annular disk 21 and the gap g ₂ between the rotating disk 11 and the movable disk 31 are set to be approximately equal. In addition, the annular disk 2
The gap g ₃ between the inner bottom surface of the first annular groove 21a and the opening side end surface of the field core 4 is set to be much larger than the gaps g ₁ and g ₂ .

Reference numeral 41 denotes an O-ring that is engaged in an annular groove 4b provided on the outer peripheral surface of the field core 4, and is connected to the outer peripheral surface of the field core 4 and the annular groove 21 of the annular disk 21.
A is sealed between the outer circumferential surface of a. 42 is an O-ring that is engaged in an annular groove 4c provided on the inner peripheral surface of the field core 4, and seals between the inner peripheral surface of the field core 4 and the inner peripheral surface of the annular groove 21a of the annular disk 21. ing. Reference numeral 43 denotes a connection plug as an introduction part for introducing pressurized fluid such as hydraulic oil or air into the pressure chamber 23. This connection plug 43 is screwed into a screw hole 21d that is bored in the outer peripheral wall of the annular disk 21 and communicates the inside of the pressure chamber 23 with the outside. Although not shown, the connection plug 43 is connected to a fluid circuit having a pressurized fluid generation source such as a pump and control means for controlling the pressurized fluid introduced into the pressure chamber 23. The control means controls the pressure chamber 23 to introduce pressurized fluid at a required pressure into the pressure chamber 23, and to open the pressure chamber 23 to the atmosphere when no pressurized fluid is introduced into the pressure chamber 23.

In the electromagnetic brake configured in this way, in a non-excited state, gaps g ₁ and gaps g ₂ are formed on both sides of the rotating disk 11, as shown in FIG. 1, so that the rotating shaft 2 is braked. Never.

On the other hand, when a voltage is applied to the excitation coil 6, the second
As shown in the figure, magnetic flux Φ is generated around the field core 4. Here, since the relationship between the gap g ₃ and the gap g ₁ is g ₃ >>g ₁ , the magnetic attraction force F ₁ of the annular disk 21 toward the field core 4 side and the magnetic attraction force F 1 of the leaf spring 24 toward the housing 3 side are The relationship between the repulsive force F ₂ and the magnetic attraction force F ₃ that attracts the annular disk 21 toward the side opposite to the field core due to the leakage magnetic flux circuit formed between the annular disk 21 and the rotating disk 11 is as follows.
Since F ₁ +F ₂ <F ₃ , the annular disk 21 has F ₁
and _F2 , and are magnetically attracted to the rotating disk 11. Therefore, the rotating disk 11 is held between the annular disk 21 and the movable disk 31, and a frictional force is generated between these members, so that the rotating shaft 2 is braked.

Next, an explanation will be given of emergency braking when it becomes impossible to apply voltage to the excitation coil 6 due to a failure in the electrical system. In this case, the fluid circuit is controlled by the control means to connect the connection plug 43 to the pressure chamber 23.
Pressurized fluid is introduced into the chamber. In this way, as shown in FIG. 3, the pressurized fluid generates a force F that presses the annular disk 21 in the direction of the rotary disk 11, and the annular disk 21 is pressed against the rotary disk 11. The rotating shaft 2 is braked by the frictional force generated between the members. The frictional force can be increased or decreased by controlling the pressure of the pressurized fluid.

Therefore, braking can be performed without attaching an emergency member as in the conventional case, and the braking force can be increased or decreased by changing the pressure of the pressurized fluid.

Here, to explain the control means, for example, when the drive source is stopped and no voltage is applied to the electrically connected excitation coil 6, the fluid circuit may be opened. By combining the circuit and the fluid circuit, emergency braking can be performed quickly and accurately.

Further, by combining the electrical system circuit and the fluid system circuit to introduce pressurized fluid into the pressure chamber 23 even in times other than emergencies, the braking force can be increased. In this case, for example, it is sufficient to provide a rotation detection device that detects the slipping of the rotary disk 11 in the state shown in FIG. 2, and open the fluid circuit with a signal output from this device. By doing so, slips of the rotary disk 11 can be reduced. Note that various fluid circuits and control means for controlling them can be considered.

FIG. 4 is a sectional view showing another embodiment, in which the same or equivalent members as those shown in FIG. 1 are given the same reference numerals and their explanations will be omitted. In this embodiment, the annular disk 21 and the movable disk 31 of the electromagnetic brake 51 are supported movably in the axial direction on bolts 52 that pass through the peripheral wall of the housing 3 from inside to outside and are fixed to the housing 3. ing. The rotary disk 21 is supported by a compression coil spring 54 interposed in a compressed state between the retaining ring 53 and the outer flange 21c.
It is urged in the direction away from 1.

Such an electromagnetic brake 51 has the advantage that a plate-shaped spring member and a structure for fixing this spring member to the housing 3 are not required.

In addition, in the above embodiment, a single flux system in which magnetic interruption parts were provided in a row was described, but the present invention is not limited to this.
It can also be used as a double or triple flux method.
In this way, the magnetic attraction force can be increased. Further, the present invention can also be applied to an electromagnetic brake in which the rotating shaft is supported in the vertical direction, and in this case, the compression coil spring 54 and the retaining ring 53 are not necessarily required.

[Effect of idea]

As explained above, according to the present invention, the annular disk made of a magnetic material is supported between the rotary disk and the field core so as to be movable in the axial direction, and has an annular groove that covers the field core from one side in the axial direction. Since the annular disk is equipped with an introduction part for introducing pressurized fluid into the pressure chamber formed between the annular disk and the field core, the annular disk can be turned into a rotating disk by introducing pressurized fluid into the pressure chamber. The rotating shaft can be braked by bringing these members into pressure contact and generating a frictional force between them.

Therefore, braking can be performed without attaching emergency components as in the past, and the braking force can be increased or decreased by changing the pressure of the pressurized fluid, so it is possible to Even when such a situation occurs, quick emergency braking can be performed, and the braking can be gradually released.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the electromagnetic brake according to the present invention, Fig. 2 is a partial cross-sectional view of the upper half showing a state where voltage is applied to the excitation coil, and Fig. 3 is a pressurized fluid inside the pressure chamber of the electromagnetic brake. FIG. 4 is a sectional view showing another embodiment. 2...Rotating axis, 4...Field core, 11...
...Rotating disk, 21... Annular disk, 23...
...Pressure chamber, 31...Movable disk, 43...Connection plug.

Claims (1)

[Scope of utility model registration request] A field core disposed coaxially with the rotating shaft, a rotating disk made of a magnetic material that is mounted on the rotating shaft opposite to the field core, and a rotating disk that extends in the axial direction between the rotating disk and the field core. An annular disk made of a magnetic material that is movably supported and has an annular groove that covers the field core from one side in the axial direction, and pressurized fluid is introduced into a pressure chamber formed between the annular disk and the field core. An electromagnetic brake characterized by having an introductory part.