SU1291758A1 - Braking device - Google Patents

Abstract

The invention relates to the field of engineering, in particular to brake devices with variable braking torque. The aim of the invention is to enhance the functionality of the braking device by providing 20 21 g 77/3 22 i9 V (L ND CL 00

Description

braking liver depending on the angle of rotation of the shaft 7. To do this, it has a correction mechanism consisting of a gear wheel 23 fixed on the shaft, a gear wheel 20 meshed with gear 23, a cam 19 and a lever 21. Inside the case 1 are spring-loaded to each other by a spring 12 weights (D) 9 and 10 with teeth 13 and 14. Between T 9 and 10 ycTaHOBJliSH one end 16 of the coil spring 15. Its other end

I The invention relates to mechanical engineering, in particular to brake devices with a braking torque variable according to a given law.

The purpose of the invention is to expand the functionality by providing a given law of braking depending on the angle of rotation of the shaft.

FIG. 1 shows the structural scheme of the proposed brake device; in fig. 2 shows the design of the device; Fig. 3 shows the laws of varying the frequency of rotation of a shaft depending on its angle of rotation.

The braking device contains a stationary body 1, inside which there is a ring 2 with protrusions 3 In case 1 there are brake pads 4, which are pressed to the ring 2 by means of springs 5, the force of which is adjusted by screws 6. Inside the ring 2, shaft 7 is mounted coaxially with it , on which the weights 9 and 10 are hinged, pressed against the stop 11 by the spring 12. The teeth 13 and 14 are rigidly connected with the weights .9 and 10, which are located a short distance from the protrusion 3 of the ring 2. Inside the shaft 7 coil spring 15, one end 16 of which is ITS weights between the ends 9 and 10. Between the other end 17 of the coil spring 13 and the housing 1 is placed correcting mechanism. In the middle position of the shaft 7, the spring 15 is in a free state.

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It is connected to the end of lever 21. Brake pads 4 are installed in case 1, interacting with ring 2. When shaft 7 is rotated and a certain amount of torque has been reached, centrifugal force is G 9 and 10, c:; 1l from spring 15 and from twist it: l spring One of the teeth (13 or 14) engages with the protrusion 3 of the ring 2. The shaft 7 is braked. The law of braking is determined by the specified cam profile 19. 3 Il.

The correction mechanism consists of a bracket 18 on which the cam 19 is hinged, rigidly connected to the gear wheel 20, and a lever 21, the axis of rotation of which coincides with the axis of the shaft 7. The force shorting between the lever 21 and the cam 19 is carried out by a spring 22. The cam 19 of the correction mechanism is driven from the gear 23, rigidly seated on the shaft 7 and engaged with the gear wheel 20. The lever 21 of the correction mechanism is rigidly connected to another

the end 17 of the coil spring 15. The device operates as follows.

When the shaft rotates 7 seconds, it is the claim 8 from its middle position, for example, counterclockwise to the weights 9 and 10, the centrifugal forces. In this case, the weight 10, interacting with the end 16 of the spring 15, begins to twist it. Therefore, besides centrifugal force, the weight 10 is exerted by the force of the coil spring 15. The other end 17 of the coil spring 15 is connected with a correcting mechanism and can rotate clockwise or counterclockwise, additionally twisting or unwinding the coil spring 15. Thereby additionally the force increases on the weight 10 from the spiral spring 15. An additional angle of rotation of the other end of the spiral spring 15 is provided by the cam

3

19 through the lever 21 of the corrective mechanism. The profile of the cam 19 of the corrective mechanism is calculated on the basis of a given law of variation in the frequency of rotation of the shaft 7, depending on its angle of rotation. Thus, the force exerted on the weight 10 from the coil spring 15 is corrected. As soon as the sum of the torque from the centrifugal force, the force of the spiral spring 15 and the additional force of the spring 15 reaches a certain amount necessary to overcome the torque from tension of the spring 12, the weight 10 moves away from the stop 11. In this case, the tooth 14 of the weight 10 engages with one of the projections 3 of the ring 2, and it begins to rotate with the shaft 7. Since the ring 2 has a frictional engagement with the housing 1, the braking torque acts on the shaft 7 until it stops.

When the shaft is rotated to the other side (clockwise) from its middle position, the braking device works in the same way. In this case, the tooth 13 of the sinker 9 is hooked to the ring 2, which, when interacting with the end 16 of the spiral spring 15, unwinds it. Since the nature of the change in the elastic moment of the coil spring 15 when twisting and unwinding is the same, then, respectively, the effect of the end 16 of the coil spring 15 on both weights 10 and 9 is the same.

In the middle position of the shaft 7, when the frequency of its rotation reaches its maximum value, and the spring 15 is in a free state, in order to ensure that the braking device operates, it is necessary that only the moment from the centrifugal force overcomes the moment from the tension of the spring 12. I

In intermediate positions of the shaft 7

when the frequency of its rotation has a certain predetermined value depending on its angle of rotation, to ensure that the braking device operates, it is necessary that the sum of the moments from the centrifugal force, the force of the spiral spring 15 and the additional force of the spiral spring 15 overcome the moment from tension of the spring 12 Moreover, the magnitude of the moment from the additional force of the spiral spring 15

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It is provided with a corrective mechanism and depends on a given law of change in the frequency of rotation of shaft 7, depending on its angle of rotation.

In the extreme positions of the shaft 7, when its frequency of rotation is equal to O, for the braking device to operate it is necessary that only the moment from the force of the spiral spring 15 overcomes the moment from the tension force of the spring 12.

Thus, in order to ensure that the braking device operates in the event that any given law of variation of the rotational speed of the shaft 7 is exceeded depending on its angle of rotation, it is necessary that the sum of the moments from the centrifugal force, the force of the spiral spring 15 and the additional force of the spiral spring 15 always overcome the tension springs 12.

The braking device can provide various laws for varying the frequency of rotation of the shaft 7 depending on its angle of rotation.

For braking device has (fig. 2)

T

R

f TC-T ,. „4

where T is the moment of operation of the braking device;

T - the moment of additional force in from the action of the spiral

the spring relative to the hinge O, i.e. moment created by the corrective mechanism.

T JL Is.

where cf. - the additional twist angle of the coil spring from the action of the correcting mechanism.

I

From the condition of the brake discontinuity

H maize

whence it is seen that the braking device can provide various laws of changing the frequency of rotation of the shaft 7 depending on its angle of rotation (Fig. 3) by changing the additional twist angle of the coil spring 15. Moreover, the additional twist angle of the coil spring 15 is determined from the condition of the brake devices by the formula

 Max

03

cot

-,

where Cf A is the additional angle of rotation of the end of the elastic element under the action of the correction mechanism; CP, - the maximum angle of rotation

 pp 01 K C

brake shaft; WITH - the current value of the frequency

rotation of the brake shaft depending on its angle of rotation;

 max is the maximum value of the brake shaft speed, Cf is the current value of the angle of rotation of the brake shaft. Thus, by changing the profile of the cam 19 in the corrective mechanism, it is possible to ensure, for example, the linear sinusoidal and parabolic laws of changing the frequency of rotation of the shaft 7 depending on its angle of rotation. So, for example, if it is necessary to provide a linear law (Fig. 3) for changing the frequency of rotation of shaft 7 depending on its angle of rotation, then the cam 19 of the correction mechanism should change the additional twist angle of the coil spring 15 according to the law

C atc-h) max

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Substituting the value c | n in the condition of the braking device's operability, we obtain the linear law of change in the frequency of rotation of the shaft 7. depending on its angle of rotation.

0

15

R

Claims (1)

Invention Formula A brake device containing a body, a brace, located in it, spring-loaded brake pads, a ring with protrusions installed inside the body with the possibility of interaction with the brake pads, a shaft with a disk on which the weights with the teeth are spring loaded to each other, and an elastic element , one of the ends of which is placed between the ends of the weights with the ability to interact with them, characterized in that, in order to extend the functionality by providing a given law of inhibition, depending from the angle of rotation of the shaft; with a cam and an elastic element connected to the free end of a 35th. 0 five 0 TC rc, etc Ф4 / г2 , Max Editor O. Yurkovetska Compiled by I.Lukina Tehred L. Serdyukova Order 218/37 Circulation 812 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab. 4/5, Production and printing company, Uzhgorod, Projecto st., 4 3 Proofreader L. Patay