RU2378543C1 - All-metal silentblock - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention is related to the field of transport machine building, in particular to elastic damping devices of control levers. Silentblock comprises two coaxially installed metal bushes and rope elastically damping element made in the form of rope rings combination. Rings are coiled from multi-cored external strand with helical elastic line in the form of hollow Mobius tores with five or six layers of winding. Layers contact each other along side surfaces at middle diametre of coaxial gap between metal bushes. All closed rope rings are installed into coaxial space between bushes with radial fit. At end surfaces of each metal bush there are two ledges, which are pressed after installation of rope rings along radius surfaces, which are equidistant to sections of extreme rope rings.

EFFECT: improved damping characteristics, resource and bearing capacity.

5 dwg

Description

The invention relates to the field of transport engineering, in particular to elastic damping devices of control levers, and can be used to reduce shock and vibration loads of units and equipment in any technical field.

There are known designs of silent blocks, consisting, as a rule, of two metal bushings and an elastic (most often rubber) insert between them. Due to the elastic insert, damping of vibrations and rattles in the joints of the parts takes place. At the same time, the silent block accounts for a significant share of the shock loads received by the vehicle suspension, and the compensation of significant deformations simultaneously in different planes and directions. Silent block provides not only angular, but also radial and axial compliance. Rubber or polyurethane elastic elements of silent blocks are made in the form of cylindrical conical or shaped sleeves vulcanized or glued to metal sleeves (see US Pat. 19847842; UK patents No. 2104590, 2112056; Japanese patents No. 4025609, 4025610, 5810971; French patents No. 2510211, 2518674).

The disadvantages of these silent blocks are: the sensitivity of the elastic damping characteristics to temperature changes, especially in the region of negative temperatures; insufficient damping; rapid aging of the elastic rubber element, accompanied by the replacement of the entire silent block.

Known annular elastic friction element, consisting of two coaxially arranged metal bushings, between which there is a package of pre-alloyed cable made by the method described in ed. USSR No. 2042064, IPC F16F 7/14. This element can be used as an elastic damping support (silent block) in transport engineering with moderate shock loads.

The disadvantage of this elasto-friction element is a reduced resource during intense vibration, accompanied by simultaneous shocks of great strength.

There is a method of manufacturing elastic-friction elements of cable vibration isolators, which consists in the fact that the elastic element is made of a multi-strand external strand of a standard pre-developed cable strand with a helical elastic line, this strand is bent into a ring with an average diameter equal to the required length of the elastic element, produce multiple in five or six layers of winding strands onto said ring with laying of turns of the free end of the screw strands equidistant to the first and subsequent layers until the screw is completely filled space of a closed loop in the form of a Moebius torus (see RF patent No. 2199683, IPC F16F 7/14).

The last two of the above analogues are selected as a common prototype.

The technical result, the achievement of which the claimed technical solution is directed, is a design with increased damping characteristics, a resource, bearing capacity and the characteristics of which are not sensitive to temperature changes.

The technical result is achieved by the fact that the all-metal silent block containing two coaxially arranged metal bushings and a rope elastic damping element, wherein the elastic damping element is made in the form of an ensemble of cable rings, twisted from a multi-strand outer strand of a standard wire rope pre-developed into strands with a helical elastic line in the form of hollows Moebius with five or six layers of winding in contact with each other on the side surfaces on the average diameter of the coaxial gap m between metal sleeves, and all closed cable rings are installed in the coaxial space between the sleeves with an optimal relative radial tightness equal to:

where δ is the radial interference in the ensemble of closed cable rings;

h = 3d - coaxial gap between the metal bushings of the silent block in an unloaded state;

d is the diameter of one screw cable strand,

and on the end surfaces of each of the metal bushings, two protrusions are made, crimped after installation of the cable rings along the radius surfaces, equidistant sections of the outer cable rings.

The invention is illustrated by drawings, where:

- figure 1 shows the appearance of the silent block with a partial section;

- figure 2 shows a view of a portion of the silent block explaining the procedure for crimping end protrusions on the bushings;

- figure 3 shows the appearance in isometric view of one twisted cable ring from an ensemble of rings;

- figure 4 shows a view of a portion of the silent block explaining the procedure for setting the optimal interference fit;

от относительного радиального натяга

при сборке сайлентблока.- figure 5 shows the dependence of the absorption coefficient ψ

from relative radial interference

when assembling the silent block.

The all-metal silent block (Fig. 1) consists of two metal bushings 1 and 2 located coaxially to each other, in the coaxial space between which there is an ensemble of cable rings 3, twisted in the form of hollow Moebius tori with five or six layers of winding and with a cavity 4 inside each Torah. Cable rings 3 are installed in the coaxial space between the bushings 1 and 2 tightly to each other and are in contact with each other on the side surfaces on the average diameter of the coaxial gap between the bushings. On the end surfaces of each of the metal bushings 1 and 2, two protrusions 5 are made (FIGS. 1, 2), crimped after installation of the cable rings along the radius surfaces, equidistant sections of the cable rings. From the sides adjacent to the two extreme rings 3 of the ensemble, the protrusions 5 have radius chamfers 6 to ensure a minimum stress concentration during deformation of the cable elements. A feature of the rings 3, twisted in the form of Moebius tori, is that each of them has only one joint of the strand 7 (Fig. 3). To ensure maximum efficiency of damping of vibrations and shock loads during the operation of the silent block, the cable rings 3 are installed in the coaxial space by the bushings 1 and 2 with the optimal relative radial interference (Figs. 4, 5) equal to:

where δ is the radial interference in the ensemble of closed cable rings;

h = 3d - coaxial gap between the metal bushings of the silent block in an unloaded state;

d is the diameter of one screw cable strand.

, обеспечивающий оптимальное значение коэффициента поглощения ψ_max (фиг.5), который определяется в виде:Specified Relative Preload

providing the optimal value of the absorption coefficient ψ _max (figure 5), which is determined in the form:

where W is the cyclic energy scattered in the silent block;

P is the potential energy of elastic deformation,

obtained by the authors by calculation and confirmed by experimental studies of a prototype of an all-metal silent block.

Compared with the rubber silent block, the absorption coefficient is at least 10 times higher than the absorption coefficients of the analogues.

All-metal silent block works as follows.

Under the action of a radial load of a vibrational or shock nature, the cable rings 3, twisted from a helical multilayer cable strand, are deformed. In this case, individual wires, slipping relative to each other, dissipate energy into the surrounding space and thereby reduce the load on the vehicle, its components and assemblies.

Claims (1)

An all-metal silent block containing two coaxially located metal bushings and a rope elastic damping element, characterized in that the elastic damping element is made in the form of an ensemble of cable rings, twisted from a multi-strand outer strand with a helical elastic line in the form of hollow tori of Möbius with five or six layers with the other along the lateral surfaces on the average diameter of the coaxial gap between the metal bushings, while all closed cable rings are installed in oaxial space between the bushings with the optimal relative radial interference equal to:

,
where δ is the radial interference in the ensemble of closed cable rings;
h = 3d - coaxial gap between the metal bushings of the silent block in an unloaded state;
d is the diameter of one screw cable strand,
and on the end surfaces of each of the metal bushings, two protrusions are made, crimped after installation of the cable rings along the radius surfaces, equidistant sections of the outer cable rings.

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