JPS62428Y2 - - Google Patents

Description

[Detailed description of the invention] This invention applies braking to the square shaft of the rotating shaft by applying pressure to both movable and fixed brake plates on both sides of a friction disk, which has a square hole in the center loosely fitted. This paper relates to improvements to disc-type electromagnetic brakes.

Conventionally, in this type of electromagnetic brake, as shown in FIGS. 5 to 8, a friction disk 13 is integrally molded with a reinforcing plate 19 made of a magnetic material and having a square hole 14 in the center, sandwiching this reinforcing plate. It consisted of a brake lining 16. Therefore, electromagnet 3
When the braking is released by the energization of
2-Rotating shaft 1-The leakage magnetic flux φ flowing in the magnetic circuit of the electromagnet yoke 4 forms an angle between the movable brake plate 9 and the reinforcing plate 19 that is close to a right angle, and the main magnetic flux φ ₀ Because a portion passes through the reinforcing plate 19, the force that attracts the friction disk 13 toward the movable brake plate 9 increases, and the friction disk 13 comes into sliding contact with the movable brake plate 9, generating a rattling sound and causing friction. This caused the disk 13 to slip off to one side.

In order to prevent this, the reinforcing plate 19 may be made of a non-magnetic material such as stainless steel, but in this case, the magnetic attraction force due to the leakage magnetic flux φ will not act between the reinforcing plate 19 and the square hub 12. The fitting portions of the two become rattled and vibrate, producing noise.

Therefore, it is necessary to insert a vibration prevention spring between the friction disk 13 and the square hub 12, which complicates the structure.

In addition, in the conventional case, the inner circumferential surface of the reinforcing plate 19 was exposed to the inner circumferential surface of the friction disk 13 over the entire circumference, so when the rotational force was transmitted, the corner of the square bub 12
As shown by the imaginary lines in the figure, the reinforcing plate 19 comes into contact with the corners of the inner circumferential surface of the square hole, generating an impact sound, and abrasion grooves are formed at the corners of the square hub 12, causing friction. The sliding movement of the disc 13 was sometimes obstructed.

The present invention solves these conventional problems,
The object is to obtain an electromagnetic brake that does not generate abnormal noise and has a long life.

Examples thereof will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 is a shaft of an electric motor, and 2 is an outer frame of the motor that supports this shaft 1. In FIG. Reference numeral 3 denotes a DC electromagnet consisting of a yoke 4 and an electromagnetic coil 5 mounted in a U-shaped groove of the yoke. Reference numeral 6 denotes a stepped stud bolt having small diameter threaded portions 8a and 8b at both ends of a large diameter main body 7. One end of the stepped stud bolt 8a is screwed into the end face of the electromagnet yoke 4 and fixed at three locations around the circumference of the electromagnet yoke. It is provided in Reference numeral 9 indicates a movable brake plate in which holes 9a provided at three locations around the circumference are loosely fitted into the main portion 7 of the stud bolt;
0 is a fixed brake plate fixed to the stepped part of the stud bolt by inserting the tip threaded part 8b of the stud bolt into holes 10a provided at three locations around the circumference and tightened to the stepped part of the stud bolt with a nut 11; 12 is a square plate fixed to the end of the rotating shaft 1; The hub 13 is a friction disk whose central square hole 14 is loosely fitted into the hub 12, and its outer peripheral end is located between the movable and fixed brake plates 9 and 10. As shown in FIGS. 3 and 4, this friction disk includes a reinforcing plate 15 made of magnetic material, and a brake lining 16 integrally molded with this reinforcing plate as a core.
The outer diameter d ₁ of the reinforcing plate 15 is smaller than the inner diameter D 1 of the end of the movable brake plate 9 on the friction disk side, and the inner diameter d ₂ is the inner diameter D ₂ of the brake lining 16 _. The projections 15a are formed at four locations around the entire inner circumference of the brake lining 16. It is exposed in the central part, and this allows the positioning of the reinforcing plate 15 during molding, as well as the reinforcing plate 1
The magnetic attraction between the hub 5 and the square hub 12 is prevented from decreasing. Reference numeral 17 denotes a braking spring stretched between the spring receiving part 9a of the movable brake plate 9 and the spring receiving part 4a of the yoke 4 between the inside of the electromagnetic yoke 4 and the rotating shaft 1. 9 to the fixed brake plate 10 side,
Both brake plates squeeze both sides of the friction disc 13,
Braking is applied to the rotating shaft 1. To release this braking, the electromagnet 3 is energized and the movable brake plate 9 is attracted to the yoke 4 against the braking spring 17. 18 is a brake cover.

As explained above, in the present invention, the outer diameter of the magnetic reinforcing plate of the friction disk is formed smaller than the inner diameter of the friction disk side end of the movable brake plate. The leakage magnetic flux φ flowing in the magnetic circuit of plate 9 - reinforcing plate 15 - rectangular hub 12 - rotating shaft 1 - yoke 4 becomes closer in the radial direction of reinforcing plate 15 between movable brake plate 9 and reinforcing plate 15. As a result, the force with which the reinforcing plate 15 is attracted to the movable brake plate 9 is smaller than the magnetic attraction force between the reinforcing plate 15 and the square hub 12 and the frictional force between the friction disk 13 and the square hub 12. hand,
The friction disc 13 is not attracted to the movable brake plate 9. Therefore, there is no possibility that the friction disk comes into sliding contact with the movable brake plate and generates a rattling sound or slips to one side as in the conventional case.

In addition, since the inner circumferential surface of the reinforcing plate is not exposed near the corner of the inner circumferential surface forming the square hole of the friction disk, even if the corner of the square hub comes into contact with this area when transmitting rotational force, there will be no metal. Contact between the hub and the molding material will not generate abnormal noise, and the sliding of the friction disk will not be inhibited due to formation of wear grooves at the corners of the square hub.

Therefore, according to the present invention, it is possible to obtain an electromagnetic brake that does not generate abnormal noise and has a long life with a simple configuration that requires only changing the shape of the reinforcing plate of the friction disk.

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view of an electromagnetic brake embodying the present invention, Fig. 2 is a front view, the right half is shown with the cover removed, and Fig. 3 is a cutaway side view with the friction disk removed. FIG. 4 is a front view, and FIGS. 5, 6, 7, and 8 are conventional drawings corresponding to FIGS. 1, 2, 3, and 4. The same symbols in the middle indicate equivalent parts. 1; Rotating shaft, 3; Electromagnet, 4; Yoke, 9; Movable brake plate, 10; Fixed brake plate, 12; Square hub, 13; Friction disc, 14; Square hole, 15; Reinforcement plate, 15a; Projection , 16; Brake lining, 17; Braking.

Claims (1)

[Scope of utility model registration request] A square hub provided on the rotating shaft, a friction disk in which a square hole in the center is loosely fitted into the hub, and both fixed and movable brake plates sandwiched between both sides of the friction disk.
It includes a brake spring that presses the movable brake plate toward the fixed brake plate to apply braking to the friction disk, and an electromagnet that attracts the movable brake plate against the brake spring to release the braking, and magnetizes the friction disk. In the electromagnetic brake, the outer diameter of the reinforcing plate is smaller than the inner diameter of the end of the movable brake plate on the friction disk side. In addition, the inner diameter of the reinforcing plate is made somewhat larger than the inner diameter of the brake lining, and the tip surfaces of the protrusions provided at several points around the inner circumference of the reinforcing plate are formed in the brake lining forming the square hole. An electromagnetic brake characterized by an exposed central part between two adjacent corners of an inner circumferential surface.