JPH02503Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a so-called excitation release type electromagnetic brake that applies braking force to a braked object by the force of a spring and releases the braking by electromagnetic attractive force, and has a simplified structure. It is an object of the present invention to provide an electromagnetic brake of this type that can reduce the axial dimension as much as possible.

First, a conventional electromagnetic brake of this type will be explained with reference to FIG. 1. In the figure, 1 is a yoke having an excitation coil 2, the right side of which is a magnetic pole surface, and the machine (not shown) in which the brake is used. fixed in place. Reference numeral 3 denotes an armature whose left side surface faces the magnetic pole surface of the yoke 1, and is capable of sliding in the axial direction on an adjustment bolt 4 which is fixed to pass through the yoke 1 laterally. A plurality of adjustment bolts 4 are arranged at equal intervals on the same circumference. Reference numeral 5 denotes an annular plate slidably fitted into the end of the adjustment bolt 4, which is prevented from falling off from the bolt by a nut 6 screwed onto the adjustment bolt, and at the same time prevents the nut 6 from rotating. Therefore, the distance of the yoke 1 from the magnetic pole surface can be changed. A release spring 7 is used to prevent the plate 5 from being attracted to the yoke 1 side due to leakage magnetism, and is fitted between the yoke 1 and the plate 5 and fitted into the adjustment bolt 4, pushing the plate away from the yoke. There is. 8 is hub 9
A brake disc is interposed between the armature 3 and the plate 5, which are engaged by splines. A plurality of braking springs 10 are inserted and supported in holes provided in the yoke 1, and bias the armature 3 to the right to press the brake disc against the plate 5 through this armature. Reference numeral 11 denotes a pin for transmitting braking torque, which penetrates the armature 3 and the plate 5 and supports them in a slidable manner.

This type of conventional electromagnetic brake consists of the above,
Normally, the brake disc 8 is compressed between the armature 3 and the plate 5 based on the pressing force of the spring 10 against the armature 3, and applies a brake to a braked shaft (not shown) that is dynamically connected to the disc via the hub 9. is applied.

When current is supplied to the excitation coil 2, the armature 3 is attracted toward the yoke 1 by the electromagnetic attraction force that resists the force of the spring 10, and the plate 5 is constantly pushed to the right by the release spring 7, Since the movement is stopped, the suction of the armature releases the clamping force exerted by the armature and the plate on the disk 8, and the brake on the braked shaft is released.

The magnetic gap between the magnetic pole face of the yoke 1 and the armature 3 can be adjusted by rotating the nut 6, since the distance between the yoke 1 and the plate 5 is changed.

In the conventional electromagnetic brake described above, the tip of the threaded part of the adjustment bolt 4 for adjusting the air gap is made to protrude from the outer surface of the plate 5, and the nut 6 is attached to this protrusion.
Since they are screwed together, the length of the adjustment bolt is
It is necessary to lengthen the plate 5 in the axial direction by the amount l that protrudes from the plate 5, which has the disadvantage of increasing the overall size in the axial direction, and furthermore prevents the plate 5 from being attracted to the yoke side due to leakage magnetism. A release spring 7 was required for this purpose.

On the other hand, this type of electromagnetic brake has conventionally been required to have high torque, high work performance, and great durability, and products that meet these requirements have been developed, but in recent years, with the spread of industrial robots, the axial dimension has been reduced as much as possible. shorten,
There has been a demand for an electromagnetic brake that can be easily stored inside a servo motor.

The present invention provides an electromagnetic brake capable of eliminating the above-mentioned conventional drawbacks and satisfying such requirements.The present invention will be described below with reference to the embodiment shown in FIG. 2.

In this figure, parts corresponding to those in FIG. 1 are given the same reference numerals, and their explanations will be omitted. In this case, a so-called countersunk screw with a countersunk head is used as the adjustment bolt 12, and with the head of the bolt buried in the plate 5, the bolt is passed through the plate 5 and the armature 3, and then the yoke is attached. Screw it into the screw hole No. 1, and then attach the collar No. 1 to this adjustment bolt.
3, the outer circumferential surface of this collar and the armature surface that connects with this surface are used as braking torque transmission surfaces, and furthermore, the nut 14 is screwed onto the adjustment bolt 12 inside the plate 5, and this nut is tightened. Adjust the plate 5 by adjusting the bolt 12.
At the same time, this adjustment bolt is prevented from rotating.

The embodiment of this proposal is structured as follows,
The basic operation of these brake bodies is no different from that of the conventional electromagnetic brake shown in FIG. In addition, rotate this bolt 12,
By changing the degree of protrusion of this bolt with respect to the yoke, and thus the distance between the yoke 1 and the plate 5, the gap can be adjusted.

In the embodiment, the adjustment bolt has a dish-shaped head, but the adjustment bolt is not limited thereto and may have a polygonal or circular shape.

In this case, by screwing the adjustment bolt into the yoke, the magnetic gap is adjusted, that is, the plate is positioned relative to the yoke, and the plate is fixed to the bolt by tightening the nut screwed inside the plate of this bolt. At the same time, this bolt is prevented from rotating, and the head of the bolt can be buried in the plate, compared to the conventional bolt head that protrudes outside the plate. The overall axial dimension can be reduced by the amount of the protrusion, and the distance between the plate 5 and the yoke 1 is fixed by tightening the nut 14. There is no need for any parts to prevent suction movement, which simplifies the structure and reduces cost.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional electromagnetic brake;
The figure is a longitudinal sectional view showing an embodiment of the present invention. 1... Yoke, 3... Armature, 5... Plate, 8... Brake disc, 10... Spring, 12... Adjustment bolt, 14... Nut.

Claims (1)

[Scope of Claim for Utility Model Registration] An armature whose one side faces the magnetic pole face of the yoke across a magnetic gap, a plate that compresses the brake disk together with the armature based on the spring force applied to this armature, and a yoke. a bolt that is screwed into the bolt and supports the armature at the intermediate portion and the plate at the head, and adjusts the magnetic gap, that is, positions the plate relative to the yoke; the bolt is screwed onto the bolt and is tightened inside the plate; An excitation release type electromagnetic brake characterized by comprising a nut that fixes the plate to a bolt and at the same time prevents the bolt from rotating.