JPS6242175B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in direct-acting electromagnetic brakes for hoists and the like.

Conventional direct-acting electromagnetic brakes have adopted a mechanism in which the electromagnet has a large stroke and a small suction force is increased through a link mechanism, and then the lever that presses the brake disc is pulled back to eliminate the pressing force. However, the amount of wear on the brake wheel and link is reflected in the lever ratio of the link and changes in the core gap of the electromagnet, so due to the relationship between the amount of variation in the core gap and the limit gap, gap adjustment is required frequently, which is inconvenient for use. It was hot. Furthermore, since a link mechanism is used, there is a drawback that the cost is high.

The present invention has been made in view of the above situation, and an object of the present invention is to provide a direct-acting electromagnetic brake that has a simple structure, can be downsized, is easy to assemble, and is easy to maintain and inspect.

The direct-acting electromagnetic brake of the present invention is connected to a motor shaft and is formed so that an electromagnet is excited at the same time as the motor is excited to compress a brake spring and release the brake on the motor shaft. an end bracket whose end is supported with a bearing interposed therebetween and has a plurality of protrusions formed on the side opposite to the motor; a mounting plate fixed to the tips of the protrusions and having a hole formed in the center; and the motor shaft. The brake wheel is slidably attached to the end of the brake wheel and can be contacted with the brake wheel, which is attached to the end bracket so as to be able to slide freely and contact the end bracket. brake disc and
The press plate is connected to the electromagnet through the movable piece fitted into the hole of the mounting plate, and the brake spring is attached between the mounting plates and biased in a direction to press the press plate against the brake disk. It is.

An embodiment of the direct-acting electromagnetic brake of the present invention will be described below with reference to FIGS. 1 to 4. FIG. 1 shows a cross-sectional view. Reference numeral 1 denotes a motor, and a cast iron end bracket 2 is fitted and fixed to one end of a housing 16 via bolts, and a motor shaft 17 of a rotor 3 has a bearing 4 attached to the end bracket 2. It is rotatably supported. A plurality of protrusions 5 (three in the illustrated case) are protruded from the side opposite to the motor of the end bracket 2, and an L-shaped mounting plate 7 to which an electromagnet 6 is fixed via bolts 19 is attached to each protrusion via the bolts 19. 5
is fixed at the tip of. A brake wheel 13 is connected to the tip of the motor shaft 17 with a spline 18 so as to be slidable in the axial direction, and both end surfaces are formed so as to be able to contact the end bracket 2 and the brake disk 14, respectively. The rear side of the brake disk 14 is in contact with a pressing plate 11 which is fixed to the electromagnet 6 and connected via a pin 10 to a movable piece 9 which is loosely fitted into a square hole 8 formed in the center of the mounting plate 7. A coil-shaped brake spring 12 is attached between the pressing plate 11 and the mounting plate 7 and is biased to press the pressing plate 11 toward the motor. Further, on the outer circumferential side of the brake disc 14, a peripheral notch 15 into which each projection 5 is loosely fitted is provided.

When assembling, the press plate 11, brake spring 12, and pin 10 are on the motor side of the mounting plate 7, so they are hidden behind the mounting plate 7, making it difficult to confirm the assembled state from the outside. As shown in the figure, before fixing the mounting plate 7 to the protrusion 5,
1. Partially assemble the brake spring 12, movable piece 9, and pin 10 with the mounting plate 7. During this partial assembly, when the square tip of the movable piece 9 is inserted into the square hole 8 of the mounting plate 7, the insertion hole for the pin 10 will protrude to the left side of the mounting plate 7 in FIG. Then, the pressing plate 11 is connected to the movable piece 9. Furthermore, the movable piece 9
is formed in such a way that it cannot be completely inserted into the square hole 8, as shown in FIG. And brake spring 1
The coil pitch of No. 2 is larger than the maximum diameter of the pin 10 because the pin 10 is inserted from the side. Further, the dimension A from the mounting plate 7 to the pressing plate 11 is smaller than the free length of the brake spring 12 and larger than the contact length of the brake spring 12. This is because when assembled as a unit, if the dimension A is larger than the free length of the brake spring 12, the brake spring 12 will fall under its own weight, and if it is assembled as is, the brake spring 12 will ride up on the pressure plate 11. There is a risk that appropriate spring pressure may not be obtained and that the brake spring 12 and the movable piece 9 may come into contact with each other. For this reason, the position of the brake spring is determined accurately by applying preload in the unit state, so that it does not shift when assembled into the end bracket 2.

When power is turned on in this direct-acting electromagnetic brake, current flows through the motor 1 and the electromagnet 6 at the same time, and the movable piece 9 is attracted. Therefore, the movable piece 9 directly pulls the pressing plate 11 away from the brake disc 14, and the pressing plate 11 compresses the spring 12 and moves to the right in FIG. 1, and the pressing force of the pressing plate 11 on the brake disc 14 is released. The rotor 3 rotates at the same time as the braking force disappears. Then, when the power is cut off, the motor 1 and the electromagnet 6 are de-energized, and the brake spring 1
The movable piece 9 and the pressing plate 11 are moved to the first position by the pressing force of 2.
The press plate 11 moves to the left in the figure, and the press plate 11 is pressed against the brake spring 1.
The brake wheel 13 is pressed by the tension of 2.
, end bracket 2 and brake disc 14
Apply pressure in between to brake.

The direct-acting electromagnetic brake of this embodiment is constructed in this way, and by making the end bracket 2 of cast iron, the bearing 4 can be placed closer to the inner diameter of the motor coil than in the case of a conventional flat steel plate product. Additionally, since stud bolts were conventionally used to support the mounting plate 7, the fixing nuts protruded toward the motor side.
In order to maintain an insulating distance from the coil, the brake part has to protrude further to the outside, but since no stud bolts are used in this embodiment, there is nothing protruding toward the coil, so the overall size can be reduced. and,
By providing the brake spring 12 between the pressing plate 11 and the mounting plate 7, the space between the pressing plate 11 and the mounting plate 7 can be used effectively. Furthermore, in this embodiment, since there is no link mechanism as in the prior art, the core gap of the electromagnet can be made small, and the electromagnet can be used in a large characteristic range with a large attractive force, so a small electromagnet is sufficient. Since the stroke is small, the impact force caused by the core collision of the suction force is small, and the collision noise is also reduced. In addition, the structure is simplified, and the main assembly can be performed after assembly as a partial unit, which facilitates assembly and maintenance.

As described above, the direct-acting electromagnetic brake of the present invention has advantages such as a simple structure, miniaturization, a small electromagnet, improved assembly, and easy maintenance and inspection.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the direct-acting electromagnetic brake of the present invention, FIG. 2 is an explanatory diagram of the combination of the end bracket and brake disc of the electromagnetic brake of FIG. 1, and FIGS. 3 and 4. 2A and 2B are partial assembly explanatory views of the pressure plate, brake spring, mounting plate, etc. shown in FIG. 1, respectively. 1...Motor, 2...End bracket, 4...
... Bearing, 5 ... Protrusion, 6 ... Electromagnet, 7 ... Mounting plate, 8 ... Square hole, 9 ... Movable piece, 11 ... Pressing plate, 12 ... Brake spring, 13 ... Brake wheel, 14 ...Brake disc, 15...Peripheral notch, 17...Motor shaft, 18...Spline.

Claims (1)

[Claims] 1. In a direct-acting electromagnetic brake that is connected to a motor shaft and formed so that an electromagnet is excited simultaneously with the motor's excitation, compressing a brake spring and releasing the braking of the motor shaft, one end of the motor shaft is connected to a bearing. An end bracket that interposes and supports the motor shaft and has a plurality of protrusions formed on the side opposite to the motor, a mounting plate that is fixed to the tips of the protrusions and has a hole in the center, and an end bracket that slides onto the end of the motor shaft. Move freely,
and a brake disc which is disposed so as to be able to face and come into contact with the brake wheel which is attached so as to be able to come into contact with the end bracket, whose rotation is restrained by the projection and whose back surface is in contact with a pressing plate, and which is fitted into the hole of the mounting plate. The linear motion is characterized in that the pressing plate is connected to the electromagnet through a movable piece, and the brake spring is attached between the mounting plates and biased in a direction to press the pressing plate against the brake disk. Electromagnetic brake.