RU2410583C1 - Protecting device - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention refers to machine building, particularly, to devices protecting objects from vibration and impact loads. The device consists of flexible elements, of an installed between them support element with an orifice, of a damping bushing positioned in the orifice of the support element, of a fixture element passing through orifices of flexible elements and of a damping bushing. A fastening bushing with flanges is arranged in the orifice of the support element between the fixture element, flexible elements and the damping bushing. Circular slots are made on surface of the fastening bushing facing the fixture element; additional damping bushings are installed in these circular slots. Value of tightening force for the fixture element is chosen by mathematic ratio.

EFFECT: increased efficiency of protection from effect of impact loads of high amplitude in cross direction.

3 cl, 4 dwg

Description

The invention relates to the field of mechanical engineering, in particular to devices for protecting objects from vibration and shock loads.

Known damping threaded connection containing interconnected mounting element base and support element, in the hole of which on the mounting element there is a sleeve with flanges and a damping sleeve covering it [USSR author's certificate No. 1572128, MKI F16B 5/02, F16F 7/08, 1988 g.].

This device allows protection against lateral loads, regardless of the parameters of the threaded connection and external load.

However, a disadvantage of the known connection is the inability to protect against vibration and shock loads in the longitudinal direction.

Known shock absorber containing elastic elements, located between them, the supporting element with the hole, a damping sleeve installed in the hole of the supporting element, and a fastening element passing through the holes of the elastic elements and bushings [USSR author's certificate No. 566469, MKI F16F 3/08, 1977 .].

This protection device is closest in technical essence to the claimed and is taken as a prototype.

The disadvantage of the prototype is the low efficiency of protection under the action of high-amplitude shock loads in the transverse direction. This is due to the almost linear, without yield point, characteristic of the radial compression strain of the damping sleeve, made, for example, of rubber, represented by the 0GA curve in Fig. 1 - dependencies F (S), where F is the load transmitted to the protected object, S is the displacement protected object relative to the protection device (deformation of the damping sleeve). The energy intensity of the protection device (potential strain energy of the damping sleeve) is the area under the OGA curve. Under shock loading, the load F _{U max} transferred to the protected object and the displacement S _{U of the} object are determined by the equality of the energy intensity of the protection device and the kinetic energy of the object.

Significantly greater energy intensity has, for example, the shear characteristic with dry friction (broken line 0BV in figure 1). Therefore, with the same offset S _{U, the} load transmitted to the protected object is much less than the load F _{U max} with a linear characteristic.

The objective of the invention is to increase the efficiency of protection under the action of high-amplitude shock loads in the transverse direction.

To solve this problem, a protection device containing elastic elements, a support element located between them with a hole, a damping sleeve installed in the hole of the support element, and a fastening element passing through the holes of the elastic elements and the damping sleeve, according to the invention, is provided with a support element located between the holes a fastening element, elastic elements and a damping sleeve, a fixing sleeve with flanges, moreover, on the surface of the fixing sleeve facing the fixing element, s ring grooves in which additional damping bushings are placed, and the fastening force of the fastener is selected from the condition of providing a shear force F _{C of the} fastening sleeve relative to the fastening element, determined by the following ratios:

F _C > F _VL ,

F _C + F _D = F _SD ,

F _LED ≤F _{U add}

where F _VL - maximum total load from vibration and linear acceleration;

F _D - the force of the radial deformation of the additional damping bushings;

F _SD - the total shear force of the mounting sleeve relative to the mounting element and the radial deformation of additional damping bushings;

F _{U add} - permissible shock load.

To ensure stability of the shear force F _{C of the} fixing sleeve relative to the fixing element, the surface of the flanges of the fixing sleeve and the surfaces of the fixing element and the base in contact with them are made with different hardness, while the elements with greater hardness have a larger diameter.

In order to provide the possibility of regulating the shear force F _{C of the} fixing sleeve, the protection device is provided with additional washers located between the flanges of the fixing sleeve, the fixing element and the base, whose surfaces are made with a hardness less than the hardness of the surfaces contacting them. _By changing the outer diameter of the additional washers, it is possible to regulate the shear force F _{C of the} fixing sleeve for a given tightening force of the fixing element.

The presence in the claimed invention of signs that distinguish it from the prototype, allows it to be considered appropriate for the condition of "novelty."

New features (the introduction of a mounting sleeve with flanges located in the hole of the supporting element between the mounting element, the elastic elements and the damping sleeve, and the introduction of additional damping bushings located in the annular grooves on the surface of the mounting sleeve facing the fastening element, as well as the choice of the value of the tightening force of the fixing fastener element from mathematical relationships) are not identified in technical solutions for a similar purpose, and therefore they provide the claimed technical solution with compliance with Itera "inventive step".

The invention is illustrated by drawings:

figure 1 shows the power characteristic of the protection device in the transverse direction F (S), where F is the shock load transmitted to the protected object, S is the offset of the protected object relative to the protection device;

figure 2 - protection device, a longitudinal section;

figure 3 - test results of the protection device for transverse shock loading by an acceleration pulse;

figure 4 - protection device with additional washers of reduced hardness, a longitudinal section.

The protection device (figure 2) contains elastic elements 1 and 2, between which is located the supporting element 3 with a hole. A damping sleeve 4 and a fastening element 5 are placed in the hole of the supporting element, with which the protection device is attached to the base 6. Between the fastening element 5, the elastic elements 1, 2 and the damping sleeve 4, a fastening sleeve 7 with flanges 8 and 9 is placed. On the inner facing the fastening element 5 of the surface of the fixing sleeve 7 is made of annular grooves in which additional damping bushings 10, 11 are placed.

The protection device operates as follows.

Under the impact on the base 6 of the shock load, the smaller shear force F _{C of the} fixing sleeve 7 relative to the fixing element 5, at which the fixing sleeve 1 is displaced, the damping sleeve 4 is deformed (section 0G of the 0GA curve in FIG. 1). When the load reaches the value of F _C and its further increase, the fixing sleeve 7 is shifted relative to the fixing element 5 with the deformation of additional damping bushings 10 and 11 (section of the main curve of the 0GD curve in figure 1). As can be seen in figure 1, the inventive device due to the more energy-intensive shear characteristics of the mounting sleeve 7, with the total energy intensity (area under the broken curve 0GD in figure 1), equal to the energy consumption of the protection device with a linear characteristic (area under the curve 0GA in figure 1 ), when displacing S _U , provides a load on the protected object equal to the total shear stress F _{SD of the} fastening sleeve 7 relative to the fastening element 5 and the radial deformation of the damping sleeves 10, 11 and lower in value transmitted F _{U max} with linear characteristics e and permissible F _{U additional} shock loads.

The embodiment of the protection device of FIG. 2, providing different hardnesses of the surfaces of the fastener 5 and the base 6 and the surfaces of the flanges 8, 9 of the fastening sleeve 7 in contact with them, has been tested experimentally and allows to reduce the shock load by about 1.6 times (see FIG. .3). Figure 3 shows the following curves:

curve A is the acceleration pulse acting on the base 6;

curve B - acceleration of the protected object in the absence of a shear protection device mounting sleeve 7;

curve B is the acceleration transmitted to the protected object by shifting the mounting sleeve 7.

To ensure stability of the shear force F _{C of the} fixing sleeve 7 relative to the fixing element 5, the surfaces of the flanges 8, 9 of the fixing sleeve 7 and the surfaces of the fixing element 5 and the base 6 in contact with them are made with different hardnesses, and the elements with greater hardness have a larger diameter.

In order to ensure the possibility of regulating the shear force F _{C of the} mounting sleeve 7, the protection device is equipped with additional washers 12, 13 of reduced hardness (figure 4). Additional washers 12, 13 are placed between the flanges 8, 9 of the mounting sleeve 7, the fasteners 5 and the base 6. Changing the outer diameter of each of the additional washers 12, 13 makes it possible to adjust the shear force F _{C of the} fixing sleeve 7 for a given tightening torque of the fastening element 5.

So, the presented information indicates the fulfillment of the following set of conditions when using the claimed invention:

- providing effective protection against transverse high-amplitude shock loads;

- for the claimed device in the form in which it is characterized in the claims, the possibility of its implementation using the means and methods described in the application and known prior to the priority date is confirmed.

Therefore, the claimed invention meets the condition of "industrial applicability".

Claims (3)

1. A protection device containing elastic elements, a support element located between them with an opening, a damping sleeve installed in the hole of the support element, and a fastening element passing through the holes of the elastic elements and the damping sleeve, characterized in that it is provided with a support element located in the hole between the fastener, elastic elements and the damping sleeve, the fastening sleeve with flanges, and on the surface of the fastening sleeve facing the fastening element, annular grooves are made, in toryh placed additional damping sleeve, with the fastener tightening torque is selected from the condition of providing shear force F _c mounting sleeve with respect to the fastener as defined by the following relationships:
F _C > F _VL ;
F _C + F _D = F _SD ;

,
where F _VL - maximum total load from vibration and linear acceleration;
F _D - the force of the radial deformation of the additional damping bushings;
F _SD - the total shear force of the mounting sleeve relative to the mounting element and the radial deformation of additional damping bushings;

- permissible shock load. 2. The protection device according to claim 1, characterized in that the surfaces of the flanges of the mounting sleeve and the surfaces of the fastening element and the base contacting with them are made with different hardness, while the elements with greater hardness have a larger diameter. 3. The protection device according to claim 1, characterized in that it is provided with additional washers placed between the flanges of the mounting sleeve, the fastener and the base, the surfaces of which are made with hardness, less than the hardness of the surfaces in contact with them, while the outer diameter of the additional washers is selected from the condition providing the required shear force F _{C of the} fastening sleeve relative to the fastener.

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