DE2650145A1 - Rotatable clamp spacer for cables - consists of inner and outer covers with grooves for rain water, and with inner screens protecting against water drops - Google Patents

Abstract

The spacer consists of a two-part inner shell element placed on the conductor, and an outer two-part element placed on the inner element. The device ensures rotation of the inner element with the cable about the cable axis. The outer element is connected to a spacing rod by a rotatable joint whose axis of rotation is perpendicular to the cable axis. The outer element (6) has near its ends, grooves (7) for rain water, and screening devices (9) inside (8) before the inner clamping area, protecting against drops of water.

Description

"Rotary clamp field spacer for bundle conductors and use

The same "The invention relates to a rotary clamp field spacer for bundle conductors made of a two-part inner shell that is clamped onto the conductor cable and a two-part outer shell body comprising the inner shell body like an umbrella, body, with a rotatability of the inner shell body including the conductor cable is guaranteed around the rope center line and the outer shell body also over a swivel joint with a vertical axis of rotation to the rope center line with the spacer rod connected is.

The invention also relates to a specific use in addition to the known purpose of the rotary clamp field spacer (s), namely bundle conductors to keep high voltage overhead lines at a distance from each other.

One such known rotary clamp field spacer has a Ball joint with two degrees of freedom of rotation (DT-AS 10 31 850). As with a rotation around a vertical axis to the rope center line is the distance between the Head rush quickly reduced, the rotation is about an additional swivel joint with an axis of rotation that is vertical to the rope center line at extreme Load allowed. This is possible if it is assumed that an extreme The load only lasts for a short time. The corresponding rotary clamp is with a shear pin equipped that shear off when a limit load in the axial direction (rope direction) is exceeded.

In the known case, however, no special measures are taken to maintain the rotation around the rope center line in case the ropes freeze.

This also applies to another known spacer with the Possibility of rotation around a vertical and a horizontal axis, in which the Possibility of rotating around the horizontal axis or around the rope center line especially for Avoidance of a kink in cross winds or short circuits is provided (DT-PS 869 683).

The invention is based on the rotary clamp field spacer mentioned at the beginning the task is to train this so that for with field spacers Coupled sub-conductors of an overhead line bundle at air and rope temperatures in the critical range from + 2 to 3 0K around the freezing point, associated with slight Iceing of the ropes, an extensive freedom of rotation is retained.

The solution to this problem is that, according to the invention, the outer shell body outer water drainage channels in its two areas surrounding the incoming ladder rope and shielding devices against water droplets in the corresponding interior cavities, Rain deflectors preferably placed on the conductor, each in front of the inner one Terminal area.

The outer shell body thus has the function of a comprehensive one Weather protection, especially against moisture.

This training makes drop-like or peg-like advantageous Avoiding ice build-up on the outer body outlet. Possibly from the direction of the longitudinal axis of the rope. Subcooled water droplets penetrating into the overall terminal body are released from the Rain deflection disks of kept away from the inner terminal area and flow via appropriately provided special bores of the inner cavities to the outside.

The rotary clamp field spacer preferably has a hinge joint, that is protected against the ingress of rainwater. With a horizontal arrangement there is a hinge cover on top. When referring to the line axis on both sides Attack directions can be a corresponding one on the hinge side of the outer shell body Seal to be attached.

The icing inside the clamp body of the rotary clamp field spacer can, according to one embodiment of the invention, additionally be prevented by that in the two rotary clamps a ring that completely or partially encompasses the conductor made of steel or other suitable material. Sizing this Ringes is done in such a way that at the rated current there are just as much additional losses as in the critical area a temperature increase of 2 to 5 ° K inside the clamp body cause.

The invention is also based on the object of long-wave rope vibrations ("Tight rope dancing") with frequencies between about 0.1 and 1 Hz and amplitudes in the order of magnitude to effectively prevent rope sagging.

The long-wave vibrations that occur at wind speeds of 10 occur up to 25 m per second, are known to occur in particular at the same time Ice accretion is particularly dangerous You are distinguished from Rope vibrations or oscillations caused by winds at lower speeds Ci up to 6 m per second), without the formation of ice, with frequencies between 5 and 40 Hz and amplitudes in the order of magnitude of the rope diameter occur and pose a risk the mechanical safety of the ropes, the material fatigue due to dynamic Alternating bending stresses.

The long-wave vibrations primarily endanger electrical safety of the lines and lead to damage as a result of arcing on the conductors. In addition, the static loads on the overhead line components additional mechanical-dynamic loads superimposed.

The most famous phenomena include those occurring throughout the 1st Conduction field extending parabolic half-waves (Fig. 1), which in the conduction direction seen, describe an elliptical trajectory (Fig. 2). The elliptical orbit of the vibrations is conceivable in a simultaneous interaction of the two Vibration components VK and HK. The size of the major axis of the ellipse can be up to 125 % of the value of the rope slack increase. In addition to the vertically emphasized elliptical Oscillations are often horizontal pendulum oscillations both in half waves as well as in irregular shapes.

Figure 3 shows the horizontal oscillation in parabolic half waves. The constant change between synchronous and asynchronous forms leads to impermissible forms Approaching neighboring phases.

In the middle of a tension field, the touch became the inner one Phases of two neighboring circuits registered (Figure 4).

The half-waves shown in Figures 1 and 2 with elliptical Trajectory and the half-waves shown in FIGS. 3 and 4 in a horizontal pendulum motion represent the most dangerous vibrations and lead as a result of close proximity and touching adjacent phases to short circuits and damage to the rope.

Less dangerous for line operation and with smaller vibration amplitudes the solid shafts or

the multiple waves between two masts.

The steady increase in line faults seen over the past decade as a result of long-wave vibrations led to the initiation of various countermeasures.

The cause of this development. And first of all: - increasing Erection of lines with bundled conductors coupled by field spacers and Single-conductor lines with larger cable cross-sections or with low torsional strength, - In the winter periods frequent interaction of certain climatic conditions.

Possible meteorological factors are: - the wind currents mentioned in the speed range of about 10 - 25 m / s, almost perpendicular to the conductors directed, - air and rope surface temperature ah freezing point, - light and aerodynamically defined ice deposits on the cables.

The following topographical and line-related influences are to be mentioned: - - Specific topography along the pipeline route and in the upstream catchment area the wind flow, - structural design, partial conductor coupling, span as well as general the vibration properties of the conductor cables.

To combat it, DT-AS 1 590 902 has a rigid one on the safety rope The aerodynamic properties of the cables are fixed in the sagging plane within the span changing and air buoyancy, welcl.e dancing is known to be resisting elongated aerodynamic dance damper. This has a completely different task. It consists in a change in the wind force one bundle is coupled to conventional field spacers and thus one Disturbance of the buoyancy forces that trigger the tightrope walk.

In contrast, the solution according to the invention consists of the above Task in the use of the rotary terminal field spacers characterized in claim 1.

Instead of an aerodynamic profile damper rigid as in the known case to be attached to the conductor, according to the invention, it is assumed that that the cause of the "tightrope" is the obstruction of the torsional tendency Conductor cables can be found by using conventional field spacers.

There are therefore rotary clamp field spacers used, the one Allow free rotation of the conductor around the center line, especially in the critical temperature range and are not very susceptible to ice accumulation.

Your task is to prevent the buoyancy aerodynamically defined ice accumulation on the ladder ropes by pushing the ladder allow undisturbed rotation. Through the swivel joint and the striving to rotate of the conductors, the unavoidable ice build-up becomes asymmetrical non-buoyant shape, thus avoiding the stimulus conditions for tightrope walking will.

For a better understanding of the torsional behavior of freely hanging conductors Some explanations are necessary: The angle of rotation of a rope is that when it is applied of a torque setting, measured from the vertical in or counterclockwise (+ j3), starting from the rest position (0 torque) a freely suspended rope stretched between two fixed points.

The torsional stiffness is a specific quantity for the torsionally elastic Properties of a rope. It depends on the structure of the rope and the manufacturing process Factors.

The torsional moment of a clamped rope is that in the free one Rope length applied moment with the generated by the rope elasticity Restoring force is in equilibrium.

Is attached to a conductor rope stretched between se fixed points with "inner Zero torque "an" external external torque "is applied, this external torque is generated in connection with the rope elasticity a certain angle of rotation13. After removal the external torque returns the torsionally elastic rope to its neutral position and thus back to the angle of rotation zero. This is also the case when using rotary clamp field spacers given according to claim 1, while in the horizontal Axis of rotation rigidly coupled field spacers, the doubled bundle conductors are torsionally rigid behavior.

The angles of rotation are proportional to the torques. Of the Angle of rotation13 starts from its maximum value in the middle of the field proportional to the length of the rope down to the zero value at the rope clamping point. Have tension changes no influence on the torsional behavior of the ropes. For the middle of a span it is true that the torsional moment is proportional to the torsional stiffness and vice versa is proportional to the span. Because of this, single ropes tend to be smaller ones Diameters and in larger spans less for dancing than single ropes with larger cross-section.

One can now based on empirical values of single-conductor cross-sections with associated spans as opposed to those in tight rope dance-specific topographies have no tightrope walking to parallel bundled lines, for the torsion force with a certain safety margin according to the rule given in the previous paragraph a safe area in a torsional torque-angle of rotation diagram for certain Define spans. However, if one wants to reduce the spans, this results for a previously determined rope cross-section a shift to the dance endangered one Area.

To solve this sub-problem in the fight against tightrope dancing are used in addition to the rotary clamp field spacers, rotary vane drives or Wind deflector profiles used, the additional torque to the inherent torque of the ice-covered Generate cable.

In a surprisingly simple way, the tightrope walk is triggered Wind flow used as a drive in order to achieve the positive, i.e. dance safe Area to generate missing differential torques artificially.

Glass fiber reinforced plastic webs are preferably used as wind deflector webs used, which are firmly connected to the conductor cable via plastic clips.

The rotary vane drives can rotate in the direction of rotation specified by the wind pressure act in equilibrium with the restoring force of the rope elasticity or also under Contribution of the rope elasticity alternately clockwise and counterclockwise. The intended alternating rotation is caused by fluctuations in the intensity of the wind current triggered.

The wind deflectors are in the narrower area of the rotary clamp field spacers mounted on the rope and dimensioned according to the following stipulations: - Compensation of the normal Rotary clamp friction.

- Compensation of the additional frictional forces of the clamp with vertical Arrangement of the rotary clamp field spacer and sag discrepancies in the sub-conductors.

- Generation of additional torque to the inherent torque of the ice-covered Conductor cable, if this is due to the structure of the cable and the laying span has insufficient inherent torsion.

It goes without saying that the rotary vane drives or wind deflector profiles can also be used for cables with single ropes.

The invention is illustrated below with reference to the drawings Embodiments explained in more detail.

They show: Fig. 1 to the already described types of long-wave Fig. 4 rope oscillations, 5 shows a section through a rotary clamp field spacer transversely to the conductor cable, FIG. 6 shows a partial section and a partial top view of the rotary terminal field spacer according to FIG. 5 parallel to the conductor cable, FIG. 7 shows a partial plan view of the rotary terminal field spacer according to Figure 5 on its hinge side and a corresponding partial section, Fig. 8 is another embodiment of the rotary clamp field spacer shown according to FIG. 5, FIG. 9 the field spacer according to FIG. 8 in the representation according to FIG. 6, FIG. 10 the field spacer according to FIG. 8 in the representation According to FIG. 7, FIG. 11, a further embodiment of the swivel joint field spacer in section parallel to the rope direction, FIG. 12 the inner shell body with groove and Spring, Fig. 13 embodiments of rotary vane drives on a conductor cable, Fig. 14 shows a wind deflector and FIG. 15 shows the fastening of the wind deflector according to FIG 14 in connection with a vertical swivel joint field spacer.

Figures 1 to 4 have already been explained at the outset.

FIG. 5 shows one for combating tightrope walking in bundle ladders usable rotary clamp field spacer 1 made of a two-part, on a conductor cable 2 to be clamped inner shell body 3, consisting of the shells 3a and 3b from Light metal alloys and / or plastics, as well as placed on the conductor cable 2 semiconducting ring guide fitting terminals 4, the inner shells 3a and 3b are through in the shells countersunk screws 5 connected to each other so that a sufficient Clamping effect is exerted on the rope 2.

The inner shells 3a and 3b are made from an outer shell body 6 Outer shells 6a and 6b like an umbrella in such a way that on the one hand good rotatability the inner shell body 3 including the conductor 2 is guaranteed and on the other hand, noise caused by rope vibrations is largely avoided will.

The outer shell body 6 is such in its further shape formed that ice adhesion connections between the outer and inner shell body 6 or 3 can be prevented. The umbrella-like embracing of the inner shell body is used for this purpose 3 in the two areas surrounding the incoming conductor cable (cf.

Fi. 7). The outer shell body 6 continues to have in both of its End areas incorporated in the surface water drainage channels 7 (Fig. 6), the Prevent drop-like or cone-like ice build-up on the outer body outlet. It is the Possibility provided for the inner cavity between the outer and inner shell body 6 or 3 to be filled with a suitable grease.

To reject from the direction of the longitudinal axis of the rope, possibly into the Entire terminal body penetrating subcooled water droplets are in inside Cavities 8 shielding devices in the form of rain deflection disks 9 are applied to the rope 2. There are bores to divert water that has penetrated up to these rain deflectors 10 out of the inner cavities 8 to the outside.

The outer shell body 6 is in a known manner with a Hinge joint 11 equipped (DT-PS 1 232 253). The hinge joint according to the invention 11, however, has a special rain cover designed on one side, in the simplest of terms Case according to FIG. 5, it is designed in such a way that there is the parting line 12 between the Outer shells 6a and 6b covered.

The outer shell body 6 is also via a swivel joint 13 on the the hinge 11 facing away from the side with the spacer bar 14 to the other sub-conductor or connected to the other outer shell body of the other sub-conductor. The axis of rotation 15 of the swivel joint 13 runs perpendicular to the representation according to FIG 5 perpendicular to the rope center line or rope direction running perpendicular to the plane of the drawing. That Swivel joint 13 is located in an extension 16 of the outer shells 6a and 6b, through which the screw 17 is guided to close the outer shells 6a and 6b. The swivel joint 13 simultaneously serves to distance the outer shell bodies 6.

When it rains, the wind forces triggering vibrations occur the ladder axis - unilaterally from the same direction, so that the vertical to be arranged Rotary clamp field spacers 1 are to be mounted in a direction-oriented manner. At a horizontal arrangement of the same is the overlap side 18 of the hinge 11 above. In relation to the line axis, permanent directions of attack belong on both sides to the exceptional cases; here can be on the hinge side of the outer shell body 6 a corresponding seal can be attached (not shown).

In contrast to the hook-shaped hinge in the sectional view according to FIG A hinge 20 with an axis 21 can also be installed on the rotary clamp field spacer 1 be provided (Fig. 8 to 10).

For this purpose, the axle 21 is fixed with an outer shell 6b tied together and passed through the other outer shell 6a with play.

The corresponding holes 22 and 23 are located within the ring area formed by the inner and outer surface of the outer shells (cf. Fig. 9), so that also in the hinge area, as with the entire construction of the rotary clamp field spacer, outwardly protruding projections largely are avoided, i.e. the overall construction is corona-safe.

The other parts according to FIGS. 8 to 10 correspond to those based on of Figures 5 to 7 described.

FIG. 11 shows an exemplary embodiment for a swivel joint field spacer 100, in which the rain deflectors 109 are integral with the ring guide fitting clamps 104 are. In this case, several can in the inner cavity 108 in the manner of a labyrinth seal Rain deflection disks 109 may be provided on the ring guide fitting terminals 104. The outer shells of the outer shell body 106 are hinged about this arrangement in a similar manner 11 and screw connection 17 closed, as shown in FIGS is. They can also have external gutters.

It goes without saying that because of the representation in portrait format such Orientation for all variants is to be imagined that with vertical rotary clamp spacers 1, 100 the bores 10, 110 actually coaxially with the spacer rod 14, 114 downwards have, whereas with horizontal rotary terminal field spacers 1, 100 the same in Angle of 900 to align the spacer 14, 114 point downwards.

In a further modification, FIG. 12 shows an inner shell body 3 'made of an aluminum alloy or of semiconducting plastic, both of which Parts 3a 'and 3b' are equipped with tongue and groove 18 and 19 so that they are in Press fit on the Can be attached to the bridle rope. The outer shell body 6 'encloses the inner shell body 3' with that required for the rotary movement Tolerance.

FIG. 13 shows various rotating blades attached to a conductor cable 2 30 can be seen. As already explained, some of these constructions work in the Direction of rotation specified by the wind pressure in equilibrium with the restoring force the rope elasticity; others work alternately with the help of rope elasticity clockwise or counterclockwise. Such rotating blades can be used in conjunction with single conductor ropes can also be used for free-hanging bundle ladders.

It is preferred in combination with the rotary clamp field spacer 1 or 100, however, a wind deflector profile 40 according to FIG. 14 is used. It consists of a glass fiber reinforced plastic web 41, which is connected via plastic clips 42 with the conductor 2 is firmly connected.

For example, FIG. 15 shows the use of a vertical rotary clamp field spacer according to FIGS. 8 to 10 in combination with wind deflector profiles 40 for vertically one above the other Bundle conductors 2, 2 'shown. Depending on the requirements, the wind deflector profiles can also be arranged below the conductor cables.

The rotary clamp field spacer allows the ropes to interfere of the buoyant ice accumulation sufficiently large turning ability, which by the appropriately dimensioned wind deflector profiles 40 is supported.

The following applies to all rotary clamp field spacers shown here: The functionality depends on the lowest possible friction resistance of the rotating clamps and keeping the clamp sliding area free of ice.

The frictional resistance that occurs is not only quantitative determined by the construction of the spacer 1 itself, but also by the there is often a difference in sag in the bundle.

The smallest sag differences are with horizontal partial conductors given. The relationships with vertical partial ladders are more complicated; because Slight differences in sag can increase the frictional resistance considerably affect; However, preventive measures can be taken during assembly care is taken to ensure that vertical sub-conductors are exactly the same sag.

The installation mode and the partial field lengths correspond to the usual technology when using conventional spacers. If it is due to the other parameters is possible, however, greater partial field lengths are preferred, around the sum of the frictional resistances of all rotary clamp field spacers 1 to be kept as small as possible.

Claims (9)

Claims 1. Rotary clamp field spacers for stranded conductors from a two-part inner shell to be clamped onto the pus rope and a two-part outer shell body encompassing the inner shell body like an umbrella, wherein a rotatability of the inner shell body including the conductor cable is guaranteed around the rope center line and the outer shell body also over a swivel joint with a vertical axis of rotation to the rope center line with the spacer rod is connected, characterized in that the outer shell body (6) in its both enclosing areas of the incoming conductor cable (2) outer water drainage channels (7) and in the corresponding inner cavities (8) shielding devices against water droplets, each in front of the inner terminal area. 2. Rotary clamp field spacer according to claim 1, characterized by a rainwater-proof hinge joint (11 21) on the outer shell body (6). 3. rotary clamp field spacer according to claim 1 or 2, characterized through bores (10) leading to the outside from the inner cavities (8). 4. Rotary clamp field spacer according to claim 1 or the following, characterized in that the inner shell body (3) is made from a light metal alloy and / or plastic and by means of attached ring guide fitting clamps (4) is attached to the conductor cable (2). 5. Rotary clamp field spacer according to claim 1 or the following, characterized in that in the two inner cavities (8) a conductor cable (2) fully or partially comprehensive, electrical loss-causing ring built in is. 6. Rotary clamp field spacer according to claim 1 or the following, characterized in that the inner shell body (3 ') in a press fit on the conductor cable (2) is held. 7. Use of rotary clamp field spacers (1,100) according to claim 1 or the following to combat long-wave rope vibrations ("tight rope dancing") high-voltage overhead lines equipped with coupled bundle conductors. 8. Use of rotary clamp field spacers according to Claim 7 in Combination with rotary vane drives (30) or wind deflector profiles (40) for generation of additional torque to the inherent torque of the conductor (2), especially the ice-covered conductor cable. 9. Use according to claim 8 of wind deflectors (41) made of glass fiber reinforced Plastic bars that are firmly connected to the conductor cable (2) via plastic clips (42) are.