RU2394325C1 - Vibration damper - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: vibration damper consists of multi-layer steel cable (2), loads (3, 4) and clamp (5). Each load is made as a ball of D diametre and a ball of d<D diametre connected with a link. The link is made in form of a cylinder with diametre d₁=(0.46÷0.54)D or a cone with diametre in base d₂=(0.35÷0.41)D and taper within limits (1:10÷1:12) and is arranged at angle of tilt α relative to vertical axis of the bigger ball. Diametre d of the ball of load (4) is calculated from ratio: d=(0.62÷0.68)D. Weight m₁ and m₂ of loads (3, 4) differ one from another and their values are chosen from ratio; also they are secured on ends of the cable (2). Loads (3, 4) are turned relative to vertical axis of damper running through lengthwise axis (22) of cable (2) at different angles α₁ and α₂ at summary angle of turn relative to each other. Cable (2) is pressed with a hexagonal matrix in opening (15) of each ball of bigger diametre by means of cylinder bushing (16).

EFFECT: facilitating optimal frequency range and value of dissipated power at various levels of vibration; also high efficiency of oscillation damping.

8 cl, 3 dwg

Description

The invention relates to the field of electric power, and more particularly to vibration dampers for wires and cables of overhead power lines.

Known vibration damper for wires and cables of overhead power lines containing an elastic damper element (cable), loads made in the form of two bell-shaped connected by a rod link rotation bodies fixed at the ends of an elastic damper element, and a clip intended for suspension of goods on the line wire [ one].

This vibration damper provides a sufficiently wide frequency range, namely, the form of vibrations, in which the load moves as a unit at the same time as the cable is deflected along its entire length, and the second vibration form, in which the load itself oscillates relative to the center of gravity, bending at the point of attachment of the cable to load, that is, this vibration damper has two natural resonant vibration frequencies and is a dual-frequency damper. However, the indicated vibration damping efficiency in this damper is achieved due to the complex shape of the goods, which leads to an increase in the complexity of manufacturing and the cost of the damper. In addition, often in practice, in order to provide a better degree of protection for the wires of overhead power lines against vibration, dampers are required that have more than two natural resonant frequencies.

The closest technical solution in relation to the proposed one is a vibration damper for wires and cables of overhead power lines, comprising an elastic damper element with at least two loads in the form of bodies of revolution fixed at its ends and a clip designed to suspend goods on a wire or cable lines [2].

The ratios between the masses of goods selected in this damper, the distance of their location on the elastic damper element to the vertical axis of the clamp, the angles of the cargo relative to each other and relative to the vertical axis of the damper are not optimal in terms of ensuring its best amplitude-frequency characteristics and improving reliability, and also improving manufacturability and reducing the complexity of manufacturing.

The applicant set himself the task of developing a new design of a vibration damper, free from the indicated drawbacks of known technical solutions and allowing to achieve improved manufacturability and reduced laboriousness of manufacture, as well as increased reliability of the damper by determining the optimal ratios of its elements in order to improve the amplitude-frequency characteristics and provide a wider scope. This technical result was achieved due to a new set of essential structural features of the claimed vibration damper, given in the following claims: “vibration damper for wires and cables of overhead power lines, containing an elastic damper element with at least two loads secured at its ends to the form of bodies of revolution and a clamp designed for suspension of goods on a wire or cable line; each load consists of a ball with a diameter D with a cut segment made at a distance L ₁ from its center, a second ball with a diameter d <D located at a distance L = (1.45 ÷ 1.65) D from the first ball, and connecting the link balls with a longitudinal axis passing through their centers and an angle of inclination α relative to the vertical axis of the large ball, an elastic damper element is fixed in the hole of each ball of large diameter parallel to its vertical axis by means of a conical part at the end of the cylindrical sleeve at a length l, the loads are made masses m ₁ = (1.01 ÷ 1.19) m ₂ , where m ₁ and m ₂ are the masses of the first and second weights, respectively, the length L _tr . _{1 of the} elastic damper element from the clamp body to the point of its closure in the first load is not equal to the length L _tr . _{2 of the} elastic damper element from the clamp body to the point of its closure in the second load, and the indicated lengths are selected from the following ratio: L _tr. 1 = (0.92 ÷ 0.99) L _tr . ₂ , the load with greater mass m ₁ is mounted on an elastic damper member at length L _tr.1 and goods with a smaller mass m ₁ is mounted on an elastic damping element lengths greater _Tr.2 L, respectively, the weight of higher mass m ₁ is deployed at an angle relative to the vertical axis of the absorber, through the longitudinal axis of the elastic damping element, α ₁ = (50 ° ÷ 80 °), and the goods with a smaller mass m ₂ is deployed at an angle relative to the vertical axis of the damper passing through the longitudinal axis of the elastic damper element, α ₂ = (40 ° ÷ 70 °) so that the goods were deployed relative to each other by the total angle α _sum. = (90 ÷ 150 °); a cut off segment of a ball with a diameter D is made at a distance L ₁ = (0.35 ÷ 0.42) D from its center; the diameter d of the smaller cargo ball is determined depending on the diameter D of the large cargo ball from the following relation: d = (0.62 ÷ 0.68) D; the link connecting the first and second balls is made in the form of a cylinder with a diameter d ₁ = (0.46 ÷ 0.54) D; the link connecting the first and second balls is made in the form of a cone with a diameter at the base d ₁ = (0.35 ÷ 0.41) D and a taper in the range (1: 10 ÷ 1: 12); the angle of inclination α connecting the first and second balls of the link relative to the vertical axis of the large ball is α = (8 ° ÷ 24 °); fixing the elastic damper element in the hole of a large ball is performed by crimping the cylindrical sleeve with a hexagonal matrix on its length 1 = (1.05 ÷ 1.15) L _hole. where L _resp. - the depth of the hole in a large ball under the cylindrical sleeve; the hole in the large cargo ball under the elastic damper element is made slightly smaller than the diameter of the cylindrical sleeve to ensure a press fit. "

The invention is illustrated by drawings, where in Fig.1 is a General view of a vibration damper, made according to the present invention, a front view, perpendicular to the wires of the line; figure 2 is the same as in figure 1, side view; figure 3 is a separate enlarged view of one load of the damper with its main geometric dimensions.

The inventive vibration damper for wires 1 and cables of overhead power lines is made in the form of an elastic damper element (multi-steel cable) 2, two weights 3, 4 and clamp 5. Weights 3, 4 are attached at the ends of the cable 2, and the case is fixed to the middle of the cable 3 clamp 5 and using a die 6, the entire damper is suspended from the wire 1 or cable overhead power lines. Loads 3, 4 are bodies of revolution, consisting of two, large and small, balls 7, 8 with diameters D and d, respectively, interconnected by a link 9 with a longitudinal axis 10 passing through the centers 11, 12 of balls 7, 8, made in the form of a cylinder with a diameter d ₁ = (0.46 ÷ 0.54) D or a cone with a diameter at the base d ₁ = (0.35 ÷ 0.41) D and a taper within (1: 10 ÷ 1: 12). The diameter d of the smaller ball 8 of cargo 3, 4 depends on the diameter D of the large ball 7 of cargo 3, 4 and is calculated from the following ratio: d = (0.62 ÷ 0.68) D. Link 9 connecting the balls 7, 8 of cargo 3, 4, is located at an angle of inclination α relative to the vertical axis 13 of the large ball, which is within (8 ° ÷ 24 °). Ball 7 is performed with a cut segment 14 located at a distance L ₁ = (0.35 ÷ 0.42) D from its center 11. The second small ball 8 with a diameter d <D is located at a distance L = (1.45 ÷ 1.65 ) D from the first ball 7.

The elastic damper element 2 is compressed by a hexagonal matrix in the hole 15 of each ball 7 of large diameter, which is parallel to its vertical axis 13, by means of a cylindrical sleeve 16 having a conical part at the end, at a length of 1 = (1.05 ÷ 1.15) L _{holes .} where L _resp. - the depth of the hole 15; moreover, the hole 15 in the large ball 7 of cargo 3, 4 under the elastic damper element 2 is made slightly smaller in diameter than the diameter of the cylindrical sleeve 16 to ensure a press fit and the reliability of securing cargo 3, 4 damper.

Loads 3, 4 at the ends of the cable 2 are made with different masses m ₁ and m ₂ with the estimated mass ratio m ₁ = (1.01 ÷ 1.19) m ₂ . The length of the cable 2 L _tr . ₁ from the clamp body 5 to the point 17 of its termination in the first load 3 differs in magnitude from the length L _tr. 2 of the cable 2 from the clamp body 5 to the termination point 18 of it in the second load 4, while the lengths of these shoulders 19, 20 of cable 2 are determined by the following ratio: L _tr. 1 = (0.92 ÷ 0.99) L _tr . ₂ . A load 3 with a larger mass m _{1 is} fixed on the shoulder 19 of a cable 2 of a shorter length L _tr . ₁ , and a load 4 with a lower mass m _{1 is} fixed on a shoulder 20 of a cable 2 of a larger length L _tr . ₂ . Relative to the vertical axis 21 of the damper passing through the longitudinal axis 22 of the elastic damper element 2, loads 3, 4 are deployed at different angles α ₁ and α ₂ , and load 3 with a larger mass m _{1 is} turned at an angle α ₁ = (50 ° ÷ 80 ° ), and cargo 4 with a lower mass m _{2 is} deployed at an angle α ₂ = (40 ° ÷ 70 °) so that the goods are deployed relative to each other at a total angle α _sum. = (90 ÷ 150 °).

The invention works as follows.

The use of the proposed vibration damper reduces the bending deformation of the wire at all dangerous points of the span of the line to a safe level according to internationally accepted standards. In this case, the most common type of oscillation of the wires of overhead power lines is aeolian vibration, as a result of which a laminar wind stream flows around the wire, which causes a synchronized breakdown of vortices with a frequency of 3 ÷ 150 Hz. As a result of such exposure, loads synchronized with the waveform develop a resonant process and wire vibration at the corresponding natural frequency. The amplitude of the oscillations in this case does not exceed the diameter of the wire at a wavelength of 1 to 20 m in the entire frequency range. Moreover, the damping efficiency of oscillations depends on the characteristics of the damper, in particular its frequency range and the magnitude of the dissipated power at various levels of vibration. The geometrical parameters of the inventive damper and its elastic damper element, which is a multi-shackle steel cable with concentrated loads fixed at its ends, are chosen in such a way as to ensure the optimality of its above characteristics, which was verified by bench tests, according to the results of which this vibration damper is recommended to industrial production.

Information sources

[one]. United States Patent Vibration damper No. 4,159,393, Class 174-42 (H02G 7/14), published June 26, 1979.

[2]. Description of the invention to the patent of the Russian Federation “Unified vibration damper” No. 229284, class H02G 7/14, filed August 18, 2003, published March 27, 2005. Bulletin No. 9.

Claims (8)

1. A vibration damper for wires and cables of overhead power transmission lines, comprising an elastic damper element with at least two loads in the form of bodies of revolution fixed at its ends and a clip designed to suspend goods on a wire or line cable, characterized in that each the load consists of a ball with a diameter D with a cut segment made at a distance L ₁ from its center, a second ball with a diameter d <D located at a distance L = (1.45 ÷ 1.65) D from the first ball, and connecting the ball links with the longitudinal axis passing through their center ntry, and an inclination angle α relative to the vertical axis of the large ball load, the elastic damper member is fixed in the bore of each ball large diameter, arranged parallel to its vertical axis, by having a tapered portion at an end of the cylindrical sleeve over a length 1, loads are made to a mass ratio of m ₁ = (1.01 ÷ 1.19) m ₂ , where m ₁ and m ₂ are the masses of the first and second weights, respectively, the length L _tr . _{1 of the} elastic damper element from the clamp body to the point of its closure in the first load is not equal to the length L _{tp. 2} by elastic damping element Corp. ca clamp to its point of termination in the second length of said loads and are selected from the following relation: L _tp.1 = (0,92 ÷ 0,99) L _tp.2, the load of higher mass m ₁ is mounted on an elastic damping element of smaller length L _tp.1 , and a load with a lower mass m _{2 is} fixed on an elastic damper element of a larger length L _tp.2, respectively, a load with a larger mass m _{1 is} rotated through an angle relative to the vertical axis of the damper passing through the longitudinal axis of the elastic damper element, α ₁ = (50 ÷ 80 °), and the cargo with a smaller mass m ₂ deployed at an angle relative to the vertical about the absorber passing through the longitudinal axis of the elastic damper element, α ₂ = (40 ÷ 70 °) so that the goods were deployed relative to each other at the total angle α _sum. = (90 ÷ 150 °). 2. The damper according to claim 1, characterized in that the cut off segment of the ball with a diameter D is made at a distance L ₁ = (0.35 ÷ 0.42) D from its center. 3. The damper according to claim 1, characterized in that the diameter d of the smaller cargo ball is determined depending on the diameter D of the large cargo ball from the following ratio: d = (0.62 ÷ 0.68) D. 4. The damper according to claim 1, characterized in that the link connecting the first and second balls is made in the form of a cylinder with a diameter of d ₁ = (0.46 ÷ 0.54) D. 5. The damper according to claim 1, characterized in that the link connecting the first and second balls is made in the form of a cone with a diameter at the base of d ₂ = (0.35 ÷ 0.41) D and a taper within (1: 10 ÷ 1: 12). 6. The damper according to claim 1, characterized in that the angle of inclination α connecting the first and second balls of the link relative to the vertical axis of the large ball is α = (8 ÷ 24 °). 7. The damper according to claim 1, characterized in that the fixing of the elastic damper element in the hole of a large ball is performed by crimping the cylindrical sleeve with a hexagonal matrix along its length 1 = (1.05 ÷ 1.15) L _otv. where L _resp. - the depth of the hole in a large ball under the cylindrical sleeve. 8. The damper according to claim 1, characterized in that the hole in the large cargo ball under the elastic damper element is made somewhat smaller than the diameter of the cylindrical sleeve to ensure a press fit.

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