RU2550914C1 - Beaded mesh vibration isolator by kochetov - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: vibration isolator comprises a base, a resilient mesh element and washers interacting with bushes. The base is made as a plate with mounting holes. The resilient mesh element is fixed by the upper and lower washers. The lower washer is rigidly connected to the base. The upper washer is connected to the central ring embraced by a coaxially set ring rigidly connected to the base. Between a packing washer and the base there installed is the resilient element made as a cylindrical equifrequent spring with variable pitch.

EFFECT: increased efficiency of vibration isolation in resonance mode.

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Description

The invention relates to mechanical engineering, instrumentation and can be used for vibration isolation of technological equipment, machine tools, devices.

It is known the use of mesh elastic elements for vibration isolation of technological equipment in the textile industry [1, 2, 3, 4]. The calculations show the high efficiency of the mesh elastic elements with their relatively small dimensions, while tests in real factory conditions confirm their effectiveness with high reliability and ease of maintenance.

Known vibration isolators mesh pendulum type [5, 6], containing a housing, an elastic element, a pendulum suspension, two coaxially located bushings are installed on the base, between which there is an elastic mesh element of the sleeve type, and the outer sleeve is higher in height than the inner one by the thickness of the pressure plate which is supported by the nut of the pendulum suspension.

The disadvantage of this type of vibration isolators with a pendulum suspension is their large height dimension, since they belong to the category of suspended vibration isolation systems, where the overall dimensions are not limited in height, and relatively small dimensions in height are required for supporting vibration protection systems.

Known vibration insulator washer mesh [7], containing a base, elastic elements, protective sleeves and pressure washers, an internal elastic mesh element is placed in the hole of the base, the inner surface of which contacts a restrictive sleeve covering the cylindrical surface of the fastener, and interact with the internal elastic mesh element external elastic mesh elements pressed against the inner element by means of pressure washers, the ratio of the outer diameter D of the external elastic mesh th element to its inner diameter d is in the range of optimal values of D / d = 3.0 ... 3.6.

The disadvantage of this vibration isolator is its relatively high rigidity, which under spatial loading is the reason for low efficiency.

Known mesh vibration isolators [8, 9, 10], respectively containing three, five and six parallel mounted mesh elastic elements located between the top cover and the base, and each of the elastic elements is made in the form of a parallel mounted spring element connected to the upper and lower pressure washers, and an elastic element in the form of a coaxially located sleeve of a three-dimensional mesh weave located inside the spring element between the pressure washers, and the fastening of the elastic elements to the cover and the base is carried out by means of coaxially arranged screws to the upper and lower pressure washers, and mounting holes are provided for fixing the base to the platform, and a plastic casing is fixed to the lid.

A disadvantage of the known vibration isolators is their relatively low ability to damp resonant vibrations.

The closest technical solution to the claimed object is a mesh vibration isolator according to the patent of the Russian Federation No. 2285839 [11] (prototype), comprising a housing, elastic elements, pressure washers, elastic elements made of parallel mounted spring element connected to the upper and lower pressure washers, and elastic an element of a volumetric mesh weave placed inside the spring element between the pressure washers and made in the form of a coaxially located sleeve, the ratio of the outer diameter D of the elastic mesh e element to its height h is in the optimal range of values D / h = 0.73 ... 1.05.

The disadvantage of this device is the lack of efficiency at resonance due to the relatively low degree of vibration damping.

The technical result is an increase in the efficiency of vibration isolation in a resonant mode.

This is achieved by the fact that in a mesh vibration isolator containing a base, an elastic mesh element and washers interacting with the bushings, the base is made in the form of a plate with fixing holes, the elastic mesh element rests on its base on the base and is fixed with a lower washer rigidly connected to the base, and the upper part is fixed by the upper pressure washer, rigidly connected to a centrally located ring, covered by a coaxially located ring, rigidly connected to the base, and between the pressure washer and the base is an elastic element made in the form of a cylindrical equal-frequency spring having a variable pitch t, ensuring the constancy of the natural frequency of the system at any loads P from a given range: P ₁ ≤P≤P ₂ , due to its precipitation δ:

where P ₁ and P ₂ respectively the minimum and maximum loads under which the conditions of equal frequency are maintained; P is the load satisfying the condition P ₁ ≤P≤P ₂ ;

δ ₁ - a given initial spring draft, corresponding to the minimum load P ₁ and the condition of equal frequency: constant frequency of natural vibrations of the vibration-insulated system when the mass of this system changes within specified limits.

In FIG. 1 shows a general view of a mesh vibration isolator; FIG. 2 is a frontal section, in FIG. 3 - an elastic element located between the thrust washer and the base, in FIG. 4 - characteristic of the equal-frequency spring.

The screen washer vibration isolator comprises a base 1 in the form of a plate with mounting holes 2, a spring elastic element 7, supported by the bottom part on the base 1 and fixed by a lower washer 6, rigidly connected to the base, and by the upper part fixed by an upper pressure washer 5, rigidly connected to a centrally located ring 4, covered by a coaxially located ring 3, rigidly connected to the base 1.

Between the pressure washer 5 and the base 1, an elastic element 8 is arranged in the form of an equal-frequency spring 11. The lower flange of the equal-frequency spring of the spring vibration isolator is mounted on the elastic base 9, and the upper one on the support plate 10, while the spring 11 has a variable pitch t, ensuring constant natural frequency at any loads P from a given range:

P ₁ ≤P≤P ₂ ,

where P ₁ and P _2, respectively, the minimum and maximum loads under which the conditions of equal frequency are maintained.

Under the action of a load P satisfying the condition P ₁ ≤P≤P ₂ , it will change its draft δ (see Fig. 2)

where δ ₁ is a given initial spring draft corresponding to a minimum load P ₁ . This corresponds to the condition of equal frequency: v = const, i.e. the constancy of the frequency of natural vibrations of the vibration-insulated system when the mass of this system changes within specified limits.

The density of the mesh structure of the elastic mesh element is in the optimal range of values: 1.2 g / cm ³ ... 2.0 g / cm ³ , and the wire material of the elastic mesh elements is steel grade EI-708, and its diameter is in the optimal range of 0 , 09 mm ... 0.15 mm.

The density of the mesh structure of the outer layers of the elastic mesh element is 1.5 times higher than the density of the mesh structure of the inner layers of the elastic mesh element.

The elastic mesh element 7 can be made combined of a mesh frame, filled with an elastomer, for example polyurethane.

The vibration isolator mesh washer works as follows.

When vibrations of a vibroinsulated object (not shown in the drawing) located on the upper pressure plate 5, the elastic mesh element 7 perceives both vertical and horizontal loads, thereby weakening the dynamic effect on the vibroisolated object, i.e. spatial vibration protection and shock protection are provided. The dry friction damper operates as follows.

Spring equal-frequency vibration isolator works as follows.

When a dynamic load is applied to the spring 3, an equal-frequency vibration isolation of the object is ensured, since the spring has a variable pitch t, which ensures the constancy of the natural frequency at any loads P from a given range:

P ₁ ≤P≤P ₂ ,

where P ₁ and P _2, respectively, the minimum and maximum loads under which the conditions of equal frequency are maintained.

Under the action of a load P satisfying the condition P ₁ ≤P≤P ₂ , it will change its draft δ (see Fig. 2)

where δ ₁ is a given initial spring draft corresponding to a minimum load P ₁ . This corresponds to the condition of equal frequency: constant frequency of the natural oscillations of the vibration-insulated system when the mass of this system changes within specified limits.

Thus, due to its selective properties, the spring provides effective spatial vibration isolation of equipment in all six directions of vibration (along three axes X, Y, Z and rotary vibrations around these axes) with vibration damping at resonance and under various operating conditions.

Sources of Bibliography

1. Kochetov O.S., Sazhin B.S. Noise and vibration reduction in production: theory, calculation, technical solutions. M: MSTU named after A.N. Kosygina, 2001 .-- 319 p.: P. 286, fig. P.Y.8 (s).

2. Kochetov O.S. Textile vibroacoustics. Textbook for universities. M .: MSTU im. A.N. Kosygina, “Sovezh Bevo” group 2003. - 191 p.: P. 60, Fig. 3.2.

3. Sazhin B.S., Kochetov O.S., Sinev A.V., Khodakova T.D. Calculation on a PC of vibration isolation systems of equipment installed on a non-rigid foundation // Life safety. - 2002, No. 12, p. 22-28.

4. Kochetov O.S. Calculation of the spatial vibration protection system. The journal "Occupational Safety in Industry", No. 8, 2009, pp. 32-37.

5. Kochetov O.S., Kochetova M.O., Khodakova T.D. Vibration isolator mesh pendulum type // Patent for invention No. 2285841. Published on October 20, 2006. Bulletin of inventions No. 29.

6. Kochetov O.S., Kochetova M.O., Khodakova TD, Kochetov S.S., Kochetov Sergey Sergeevich. Vibration isolator mesh pendulum // Patent for invention №2285842. Published on October 20, 2006. Bulletin of inventions No. 29.

7. Kochetov O.S., Kochetova M.O., Khodakova T.D., Shesterninov A.V., Stareev M.E. Vibration isolator washer mesh // Patent for invention No. 2288388. Published on November 27th, 2006. Bulletin of inventions No. 33.

8.Kochetov O.S., Kochetova M.O., Khodakova T.D., Stareev M.E., Lvov G.V., Lvova N.A., Lvova Yu.G., Kulichenko A.V., Kochetov S.S., Kochetov Sergey Sergeevich. Vibration isolator // Patent for invention No. 2285840. Published on October 20, 2006. Bulletin of inventions No. 29.

9. Kochetov O.S., Kochetova M.O., Khodakova T.D., Kochetov S.S., Kochetov Sergey Sergeevich. Kochetovs vibration isolator // Patent for invention No. 2288385. Published on November 27th, 2006. Bulletin of inventions No. 33.

10. Kochetov O.S., Kochetova M.O., Khodakova TD, Kochetov S.S., Kochetov Sergey Sergeevich. Vibration isolator Kochetova // Patent for invention No. 2288386. Published on November 27th, 2006. Bulletin of inventions No. 33.

11. Kochetov O.S., Kochetova M.O., Khodakova T.D., Stareev M.E., Lvov G.V., Lvova N.A., Lvova Yu.G., Kulichenko A.V., Kochetov S.S., Kochetov Sergey Sergeevich. Vibration isolator spring mesh // Patent for invention No. 2285839. Published on October 20, 2006. Bulletin of inventions No. 29.

Claims (4)

1. Vibration isolator mesh washer containing a base, an elastic mesh element and washers interacting with the bushings, characterized in that the base is made in the form of a plate with mounting holes, the mesh elastic element with its lower part rests on the base and fixed with a lower washer rigidly connected to the base and the upper part is fixed by the upper pressure washer rigidly connected to the centrally located ring, covered by the coaxially located ring, rigidly connected to the base, and between the pressure w the elastic element located in the form of a cylindrical equal-frequency spring having a variable pitch t, which ensures the constancy of the natural frequency of the system at any loads P from a given range: P ₁ ≤P <P ₂ due to its precipitation δ:
$$\delta ={\delta }_{\mathrm{one}}\left(ln\frac{P}{P_{\mathrm{one}}}+\mathrm{one}\right)$$

,
where P ₁ and P ₂ respectively the minimum and maximum loads under which the conditions of equal frequency are maintained; P is the load satisfying the condition P ₁ ≤P≤P ₂ ;
δ ₁ - a given initial spring draft, corresponding to the minimum load P ₁ and the condition of equal frequency: constant frequency of natural vibrations of the vibration-insulated system when the mass of this system changes within specified limits. 2. Mesh washer vibration isolator according to claim 1, characterized in that the density of the mesh structure of the elastic mesh element is in the optimal range of values: 1.2 g / cm ³ ÷ 2.0 g / cm ³ , and the wire material of the elastic mesh elements is steel EI-708 brand, and its diameter is in the optimal range of 0.09 mm ÷ 0.15 mm. 3. The mesh washer vibration isolator according to claim 1, characterized in that the density of the mesh structure of the outer layers of the elastic mesh element is 1.5 times higher than the density of the mesh structure of the inner layers of the elastic mesh element. 4. The screen washer vibration isolator according to claim 1, characterized in that the elastic mesh element is made combined of a mesh frame filled with an elastomer, for example polyurethane.

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