JPS6317864Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic brake, and more particularly to noise countermeasures for a single-plate non-excitation type electromagnetic brake.

Noises generated in electromagnetic brakes include a so-called rattling noise caused by collisions between members, and a so-called scraping sound caused by friction between members.

Fig. 1 shows an example of a conventional electromagnetic brake, in which numeral 1 is an electromagnet, and an armature 2 guided by a pin is placed opposite the magnetic pole surface of the electromagnet, and a friction plate is placed on the opposite side of the armature 2 to the electromagnet. 3 and a hub 4 are arranged in sequence, and the hub 4 is fixed to a shaft indicated by a dashed line with a holding nut 5 and a mounting bolt 6. When the electromagnet 1 is deenergized, the armature 2 is pressed against the friction plate 3 fixed to the hub 4 by a coil spring 7 acting in a direction opposite to the electromagnet.
When the electromagnet 1 is energized, the armature 2 is attracted to the electromagnet 1 against the acting force of the coil spring 7, and the armature 2 and the friction plate 3 are separated. In other words, it is configured as an electromagnetic brake that operates without excitation.

Here, the shaft portion to which the hub 4 is attached has a small diameter due to various dimensional constraints, and may be bent due to work on the electromagnetic brake device or the like. As a result, the surface of the armature 2 and the surface of the friction plate 3 are not kept parallel, and the armature 2 and the friction plate 3 do not come into surface contact when the brake is applied, so a sliding phenomenon occurs between them, causing a so-called nudging noise. Occur.

In the case of equipment to which electromagnetic brakes are applied, such as office machines, this nudging noise may be mistaken for a failure of the office machine itself, and in the case of medical equipment, it may increase patient discomfort, so countermeasures should be taken. is requested.

The present invention has been made in view of the above points, and it is possible to make surface contact between the friction plate and the armature regardless of the bending of the shaft by interposing an elastic member between the friction plate and the shaft without using a single plate. This is an excitation operated electromagnetic brake.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, the same reference numerals as in FIG. 1 indicate the same elements, and a hub member 8 and a leaf spring 9 are provided in place of the bub 4 in FIG. The leaf spring 9 has an elastic force stronger than the elastic force of the coil spring 7,
Its inner circumference is the presser nut 5 and the mounting bolt 6
The friction plate 3 is fixed to the hub member 8 by means of rivets or screws to the outer peripheral portion.

As a result, if the part where the hub member 8 of the shaft is attached is bent and as a result the surface of the friction plate 3 cannot be kept perpendicular to the axial direction and the electromagnetic brake is activated, the friction plate 3 will move against the armature 2. Immediately after the friction plate 3 and the armature 2 partially come into contact and slide, they immediately come into surface contact, and no friction noise, that is, a scraping sound is generated.

As mentioned above, the present invention has a leaf spring interposed between the friction plate and the shaft, so even if the shaft is bent, the friction plate and the armature can be brought into surface contact. Since they are fixed with rivets or screws, the leaf spring can absorb the vibration of the friction plate well. Therefore, it is possible to completely prevent the rattling noise that is generated when the friction plate and the armature partially come into contact with each other and slide.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional non-excitation operated electromagnetic brake, and FIG. 2 is an explanatory diagram showing an embodiment of the present invention. 1... Electromagnet, 2... Armature, 3... Friction plate, 4... Hub, 5... Holder nut, 6... Mounting bolt, 7... Coil spring, 8... Hub member, 9... Leaf spring .

Claims (1)

[Scope of utility model registration request] an electromagnet; a spring disposed opposite to the electromagnet; and a spring that applies an acting force to separate the electromagnet;
an armature that is attracted to the electromagnet by the energization of the electromagnet; a friction plate that is disposed on the opposite side of the armature and comes into contact with the armature when the electromagnet is deenergized; a hub member fixed to the shaft; and an inner periphery. is fixed to the hub member, and a leaf spring whose outer periphery is fixed to the friction plate with rivets or screws to connect the hub member and the friction plate.