EP2331660A2

EP2331660A2 - Cable lubricant

Info

Publication number: EP2331660A2
Application number: EP09748207A
Authority: EP
Inventors: Richard Phillips; Daniel Schlesier; Tim Schwarzer
Original assignee: Brugg Drahtseil AG
Current assignee: Brugg Drahtseil AG
Priority date: 2008-10-30
Filing date: 2009-10-29
Publication date: 2011-06-15
Also published as: WO2010048736A2; CN102203227A; CH699751A1; WO2010048736A3; KR20110090902A

Abstract

A dry lubricant (50) for flexible traction members (10), in particular wire cables and/or stranded ropes for static and/or dynamic loads, is characterized in that a major percentage of the dry lubricant (50) consists of a polymer material. Furthermore, in a method for manufacturing a flexible traction member (12) made up of multiple tension-proof elements (1.1, 1.2,..., 1.7, 20), in particular wires and/or strands and/or ropes, a dry lubricant (50) is applied to the tension-proof elements (1.1, 1.2,..., 1.7, 20) before the latter are joined together, said dry lubricant (50) being sprayed onto the tension-proof elements (1.1, 1.2,..., 1.7, 20) in a fluid state.

Description

rope lubricant

Technical area

The invention relates to a dry lubricant for flexible tension members, in particular wire ropes and / or stranded cables for static and / or dynamic loads. Furthermore, the invention relates to a method for producing a tension member and the use of a dry lubricant in the manufacture of a flexible tension member. State of the art

Deflectable tension members, such as, for example, tension cables or tension cables, are indispensable mechanical components, in particular in conveyor technology, bridge construction and general construction, which permit the transmission of tensile forces. Detachable traction elements usually consist of several individual elements, such. As wires or tensile fibers, which are stranded and / or twisted into strands and serve as traction elements. Several strands can also be stranded or twisted into larger ropes or traction elements and / or provided with a common sheathing, for example made of a plastic.

Tension members can serve, for example, as static elements, in particular in the form of guy ropes. But it is also possible to use tension members for power transmission in dynamic applications, for example in conveyor technology.

In particular, traction elements, which are exposed to a constant alternating load, wear after a certain period of use and must therefore be replaced periodically. The wear of the traction elements is to be attributed, inter alia, to the rubbing against each other individual elements and / or strands. Particularly affected by fretting are traction elements, which are used for dynamic applications, as they are subject to constant flexing during deflection and / or winding and unrolling.

In practice, therefore, inter alia attempts to reduce the frictional forces between the individual elements and / or strands of a tension member by these in the manufacture of the tension member, for example, with oil and / or grease-based lubricants in pasty form, which may optionally contain additional lubricant particles, be treated.

From US 4,563,870 (United States Steel Corporation) wire ropes are known which z. B. are intended for use in cranes, elevators or ski lifts. The wire ropes have a core strand and outer strands, which are lubricated on the outside and on the inside with a high-viscosity lubricant. The lubricant, which z. On tar or asphalt based materials and containing at least 5% solids in the form of graphite or molybdenum sulfide is applied to each strand during the manufacturing process.

Also known is the use of solid lubricants without additional binder. US 1,730,741 (Munford) discloses z. As steel wires or cables with individual wires, which with a dry lubricant such. As graphite, coated and wound spirally.

Although in such lubricated traction elements, the frictional forces between the individual elements or the strands are initially reduced. In particular, in dynamic applications, however, the flowable and / or pulverulent lubricant are pushed out of the pulling member over time due to the alternating loads and / or the flexing work, so that their lubricating effect in the tension member wears off. In addition, the lubricant forced out of the pulling member can, for example, contaminate the machine components coming into contact with the pulling member. This is so disadvantageous in particular in the case of friction drives distributed in the conveying area that in this case lubricant is usually dispensed with in the tension members and an accelerated wear of the tension member is accepted.

There is therefore still a need for a lubricant for tension members, which does not have the disadvantages mentioned above.

Presentation of the invention

The object of the invention is therefore to sharpen a the technical field mentioned above belonging lubricant for traction elements, which has a lasting and effective lubricating effect.

The solution of the problem is defined by the features of claim 1. According to the invention, a major proportion of the dry lubricant is a polymeric material. In this context, a dry lubricant is understood as meaning a lubricant which is preferably present at a working temperature of at least 70 ^° C., in particular up to at least 80 ^° C. and very particularly preferably up to at least 110 ^° C., in solid form or as a solid. As a solid, the dry lubricant according to the invention is in particular not flowable. Advantageously, the lubricant without additional suspending agent, such as. As oils, fats and / or liquids are used.

The phrase "a major portion of the dry lubricant is a polymeric material" means that the polymeric material is the component with the largest proportion of the composition of the dry lubricant. In principle, the proportion of the polymer material can also be less than 50%, provided that the other components of the dry lubricant have a smaller proportion than the polymer material. However, the proportion of the polymer material in the dry lubricant is preferably at least 50% by weight, particularly preferably at least 75% by weight.

The polymeric material may include, for example, homopolymers of a single monomer type and / or copolymers of different monomer types. The homopolymers and / or copolymers can also be crosslinked with one another. In principle, the polymer material may also include ionomers which are ionically crosslinked. Also mixtures of different types of polymers may be included in the polymeric material.

It has been found that the dry lubricants according to the invention, which are arranged on the individual elements and / or strands of a tension member, produce an extremely effective lubricating effect with a major proportion of a polymer material. By the dry lubricant adjacent individual elements and / or strands are at least partially kept at a distance. Direct contact between the individual elements provided with the dry lubricant and / or strands is reduced so much, which significantly reduces the fretting wear in the tension member. These effects occur both in traction elements with metallic individual elements, such as. As wire ropes, as well as tension members with synthetic fiber materials as individual elements, such as. As fiber ropes, a. It was found that even with continuous deflection processes of a tension member and especially at temperatures of 70 ⁰ C and more, the dry lubricant disposed therein hardly migrated in the tension member and only to a small extent grated or crushed. On the one hand, this results in a permanent lubricating effect and, on the other hand, the dry lubricant remains relatively stationary in the traction element. A working out or a separation of the dry lubricant from the interior of the tension member to the outside and / or a release of the dry lubricant to the environment of the tension member is best prevented due to the nature of the dry lubricant.

Since the dry lubricant according to the invention remains relatively stationary in the tension member, it can also be used without problems in tension members with an outer shell. In this case, the dry lubricant is applied, for example, only in inner regions of the tension member, while the coming into contact with the shell areas of the individual elements and / or strands are free of dry lubricant. This is both a good adhesion between casing and tension member given, which is important, for example, for an effective train transmission in friction drives, as well as adequate lubrication by the dry lubricant in the inner regions of the tension member.

Comparisons between tension members with dry lubricants according to the invention and non-lubricated tension members have given the traction elements with dry lubricants according to the invention a life of 2-3 times longer.

The dry lubricants according to the invention can be applied to the surfaces of the individual elements of the tension members, in particular by the majority of polymer material, with the formation of relatively strong adhesion forces. The adhesion forces are based in particular on molecular interactions in the boundary layer between the dry lubricant and the surface of the individual elements. The application can z. B. at elevated temperatures, in which the polymer material softens or is melted. As a result, the polymer material can in particular be molded onto the surface of the individual elements, resulting in a microscopic scale mechanical interlocking between the dry lubricant and the surfaces of the individual elements result.

In addition, polymer materials which form the main constituent of the dry lubricant according to the invention are generally significantly less toxic than the oils and greases often used for rope lubrication. This results in essential advantages of the novel dry lubricants also with regard to environmental compatibility.

The polymer material is preferably halogen-free. It has been found that, in particular in the use of halogenated polymer materials, such. As polytetrafluoroethylene, the life of the tension member is reduced in comparison with halogen-free polymer materials. The shorter life of the traction elements with halogenated polymer materials is likely to lead to the formation of corrosive compounds such. As HCl or HF, be led back. Such corrosive compounds arise in particular with ongoing deflections of the traction elements.

If the polymer material is heated when it is applied to the individual elements and / or strands for the purpose of softening and / or melting, halogenated polymer materials represent a considerable danger to humans and the environment, since in some cases toxic gases are formed. This is best prevented by the use of halogen-free polymer materials.

In principle, it is also possible to use halogenated polymer materials, if their advantages, for example, outweigh the disadvantages mentioned above.

In particular, the polymer material comprises a thermoplastic polymer having a melting point of at most 300 ^° C. Such polymers have proven to be particularly effective dry lubricants which optimally extend the life of a tension member. This in particular if the polymer is additionally halogen-free. In addition, thermoplastic polymers can be melted and solidified again without any problems, which is of great advantage for the application of the dry lubricant to the individual elements and / or strands of the tension members. The melting point of at most 300 ° C allows in particular an energy-efficient melting and thus a economical application of the polymer to the individual elements and / or strands of the tension member.

In principle, however, it is also possible to dispense with thermoplastic polymers. It is also possible to use thermoplastic polymers having a melting point above 300 ⁰ C. However, these hardly bring any advantages, but require more enegry when melting, which is less economical.

Preferably, the thermoplastic polymer comprises a polyolefin, wherein the polyolefin is in particular ethylene vinyl acetate and / or polyethylene and / or polypropylene. Polyolefins are characterized in particular by a good chemical resistance and are also easy to process. Ethylene vinyl acetate, polyethylene and / or polypropylene, which are preferred representatives of polyolefins in this context, have proven to be particularly stable and effective dry lubricants which are able to optimally extend the life of a tension member. In addition, such polyolefins are halogen-free and form even at high mechanical loads, such as. B. caused by deflecting the tension member, hardly corrosive gases. In principle, however, other thermoplastic polymers can be used as polyolefins.

Particular preference is given as a thermoplastic polymer or polyolefin ethylene vinyl acetate having a density of 0.90 - 0.96 g / cm ³ and / or a melting temperature of 60 - 100 ⁰ C before. In particular, the ethylene vinyl acetate has a melt flow index (= melt flow index) of 1.0 - 43.0 g / 10 min at a test temperature of 190 ⁰ C and a test load of 2.16 kg. To determine the melt flow index, the thermoplastic polymer is melted at the test temperature and pressed under a pressure generated by the test load in a conventional manner through a defined nozzle. Subsequently, the mass of the polymer melt emerging from the nozzle is determined as a function of time. More preferably, a Shore hardness of ethylene vinyl acetate is 24-45 Shore D. The determination of the Shore hardness succeeds according to a known and standardized method. Also preferably, the thermoplastic polymer comprises low density polyethylene, which is often referred to as low density polyethylene (abbreviation: LDPE or PE-LD). A density of the polyethylene is in particular from 0.90 - 0.94 g / cm ³ and / or a melting temperature in the range 100-120 ⁰ C. In particular, the polyethylene has a melt flow index (= melt flow index) of 0.1 - 40.0 g / 10 min at a test temperature of 190 ⁰ C and a test load of 2.16 kg. More preferably, a Shore hardness of the polyethylene at 20 - 60 Shore D.

Ethylene vinyl acetate and / or polyethylene having the above given densities, melting temperatures, melt flow indices and / or Shore hardness have been found in the context of the invention to be particularly suitable. In particular, such ethylene vinyl acetates and / or polyethylenes for use as dry lubricants in ropes have an optimum viscosity in combination with a very high resistance. This allows the life of a tension member to extend further. In principle, however, it is also possible to use ethylene-vinyl acetates and / or polyethylenes having other properties.

In a further preferred embodiment, the thermoplastic polymer comprises a mixture of ethylene vinyl acetate and polyethylene, wherein the ethylene vinyl acetate and the polyethylene used in this case advantageously have the corresponding densities, melting temperatures, melt flow indices and / or shore hardnesses given in the preceding paragraphs.

More preferably, the thermoplastic polymer comprises a polyester and / or a polyamide. The polyester is in particular polybutylene terephthalate and / or polyethylene terephthalate. Polyester and polyamides are characterized in particular by high strength and dimensional stability, even at elevated temperatures. It has been shown that polyester as well as polyamides as dry lubricants in traction devices also have very good lubricating properties and therefore allow a durable and effective lubrication. In principle, however, other thermoplastic polymers can also be used as polyesters and / or polyamides. Also preferably, the thermoplastic polymer comprises a thermoplastic elastomer, in particular polyurethane and / or a thermoplastic polyester elastomer. Thermoplastic elastomers also have good and lasting lubricating properties in tension members. Due to the thermoplastic properties, deratige polymer materials can also melt in a simple manner and thus apply well to the individual elements and / or strands of the traction elements. However, it is also possible to provide thermoplastic polymers other than thermoplastic elastomers.

In a further preferred variant, the polymer materials are in the form of mixtures of different polymers, in particular mixtures of polyolefins and / or polyesters and / or polyamides and / or thermoplastic elastomers. Thus, the properties of the polymer materials can for example be adapted specifically to the properties of the individual elements and / or strands of the tension member. In principle, however, the polymer material can also have only one single type of polymer, which in particular simplifies a production process for the dry lubricant.

The thermoplastic polymer preferably has a proportion of at least 50%, in particular at least 75%, in the dry lubricant. Thus, in particular, a meltability of the dry lubricant is ensured, which in turn simplifies the application of the dry lubricant to the individual elements and / or strands of the tension member and improves the adhesion. But it is also possible to provide a dry lubricant with a lower proportion or no thermoplastic polymer.

In a further preferred variant, the polymer material comprises a thermoset. A thermoset can be present for example as uncured and optionally liquid precursor, which is mixed shortly before application to the individual elements and / or strands with a hardener component and then cured. Also conceivable is the use of thermosets, which can be cured directly on the individual elements and / or strands of the tension member under the influence of heat and / or electromagnetic safe radiation. In principle, however, it is also possible to use another polymer material which does not contain any thermosets. It may also be advantageous if the dry lubricant additionally contains a wax, wherein the wax is preferably a synthetic polyethylene wax and / or a synthetic amide wax. Thus, in particular, the lubricity of the dry lubricant can be further improved. Polyethylene waxes and / or amide waxes, which can also be used as a mixture, have proven to be particularly suitable. Dry lubricants with such waxes remain stable for a long time even under heavy mechanical loading of the traction elements. There is hardly any segregation of wax and polymer material. In particular in combination with thermoplastic polymers, said polyethylene waxes and / or synthetic amide watch have proved to be advantageous.

Particularly preferably, the dry lubricant comprises a synthetic amide wax of a fatty acid amide ester. A melting point of the amide wax synthetic amounts to preferably 50 - 80 ^0C and / or a density is 0.9 - 1.1 g / cm ^3. Synthetic amide waxes having an acid value of 0.015-0.040 mg KOH / g have proven particularly advantageous.

In a further preferred embodiment, a polyethylene wax is present in the dry lubricant. Advantageously, the polyethylene wax has a melting point of 105-120 ° C. and / or a density of 0.90-0.93 g / cm ³ . Polyethylene waxes with an acid value of 0.01-0.1 mg KOH / g have proven particularly suitable.

By synthetic amide waxes and / or polyethylene waxes having the above-mentioned melting points, densities and / or acid values, in particular, the lubricity and long-term stability of the dry lubricant can be further improved.

But it is also possible, for example, other types of wax, z. As natural waxes, use or entirely to dispense with the addition of waxes.

In particular, additional additives in the form of viscosity modifiers and / or antioxidants and / or corrosion inhibitors are included. This can be improved in particular the long-term stability of the traction elements. By the Antioxidants and / or corrosion inhibitors, the individual elements and / or strands of the tension members best possible against environmental influences such. As moisture and / or oxidizing gases are protected. This is particularly advantageous for metallic individual elements and / or strands. Furthermore, the plasticizers of the dry lubricant can be adjusted by the viscosity modifiers, which in turn makes it possible to optimize the lubricating effect.

However, such additional additives are not mandatory and can also be omitted, for example, to minimize costs during production.

Advantageously, a thermoplastic hot melt adhesive is additionally contained in the dry lubricant. In particular, the adhesion between the dry lubricant and the surfaces of the individual elements and / or strands can thus be improved. Surprisingly, it has been found that the hot melt adhesive does not affect the lubricity. On the contrary, the additional thermoplastic hot melt adhesive provides significant advantages by further improving the long term stability of the tension members. Thermoplastic hot melt adhesives can be melted and liquefied, so that, for example, in the preparation or provision of dry lubricant this can be added in a simple manner. In principle, however, it is also possible to dispense with a hotmelt adhesive in the dry lubricant.

Advantageously, the thermoplastic hot melt adhesive has a polyolefin base. Such hot melt adhesives are characterized by good chemical resistance. If, in addition, halogen-free polyolefins are used, they are also formed in the case of large mechanical loads, such as, for example, B. caused by deflecting the tension member, hardly corrosive gases. In principle, however, hot melt adhesives based on non-polyolefin, z. B. polyamide-based, are used.

In particular, the thermoplastic hot melt adhesive has a softening point of at least 71 ± 5 ° C. In addition, at a temperature of 23 ° C., a density of the hotmelt adhesive is in particular 0.87 + 0.03 g / cm ³ . More preferably, the thermoplastic hot melt adhesive at a temperature of at least 80 ⁰ C a Melt viscosity of at least 130 ± 25 mPa-s. Ideally, the thermoplastic hot melt adhesive has a softening point of 71 ± 5 ° C. Particularly preferably, the thermoplastic hot melt adhesive at a temperature of 80 ⁰ C, a melt viscosity of 130 ± 25 mPa s. Dry lubricants with such hot melt adhesives have proved to be optimal with respect to adhesion or adhesion of the dry lubricant to the individual elements and / or strands and with respect to the lubricating effect in the tension member. Thus, maximum long-term stability or lifetimes of the traction elements treated with it were achieved.

But it is also possible to use hotmelt adhesives with other softening points and / or densities and / or melt viscosities. However, the long-term stabilities are thereby reduced.

Advantageously, the thermoplastic hot melt adhesive has a proportion of at least 1% and less than 50%. This guarantees a good adhesion of the dry lubricant to the individual elements and / or strands of the tension members, but at the same time the good lubricating properties of the dry lubricant are maintained. Although lower shares than 1% are also possible, but the effect of improved adhesion hardly occurs. Likewise, it is basically possible to provide a proportion of the hotmelt adhesive of 50% or more. However, the lubricating effect of the dry lubricant decreases rapidly.

In a further preferred embodiment, the dry lubricant contains an additional coupling agent (coupling agent), which in particular comprises an aminosilane. Particularly preferably, the additional adhesion promoter consists exclusively of aminosilane. As has been found, in particular an aminosilane having a density of 0.90 - 0.97 g / cm ³ and / or a boiling point of 200-240 ⁰ C and / or a flash point greater than 95 ° C is advantageous. In particular, adhesion and / or adhesion of the dry lubricant to the individual elements and / or strands of a rope can be increased by the additional adhesion promoter, with which the long-term stability or service life of the tension elements can be increased. In principle, however, it is also possible to dispense with an additional adhesion promoter or a primer without aminosilane can be used.

In a flexible tension member, comprising a core strand and at least one outer strand surrounding the core strand, the dry lubricant according to the invention is preferably arranged on a surface of tensile individual elements, in particular wires and / or strands and / or fibers, of the core strand. Lubrication in the region of the core strand has proven to be a decisive measure for extending the service life or reducing the fretting wear of the traction elements. In principle, it is also possible to dispense with the attachment of the dry lubricant in the core area and instead to attach the dry lubricant, for example in the range of outer strands of the tension member.

In particular, however, it may be advantageous if an outer surface of an outermost layer of outer strands of the flexible tension member is free of dry lubricant. Thus, the tension member can be used conventionally in friction drives, since the coming into contact with the components of the friction drive portion of the tension member are free of dry lubricant. Due to the relatively stationary dry lubricant, as explained above, there is no risk of it getting into the outer region over time and impairing the friction of the tension member in the friction drive, for example on a traction sheave.

Preferably, the dry lubricant arranged has an areal density of at least 1 g / m ² , based on an outermost surface area of the tension member, the areal density preferably being 1-20 g / m ² . In this context, the outermost peripheral surface is understood to be the outermost boundary surface of the tension member which delimits the tension member in the radial direction. Thus, a sufficient lubricating effect is achieved, which significantly reduces the Reibverschleiss and increases the life of the tension member. The preferred surface densities of 1-20 g / m ² are relatively low compared to conventional lubricants. Lower surface densities than 1 g / m ² are also possible, but the lubricating effect decreases rapidly. enlarge the Area densities as 20 g / m ² are also feasible, but bring little further increases in the life of the traction elements.

In particular, the dry lubricant is in the form of individual particles, wherein the individual particles form a coating that covers the surface of the tensile individual elements of the core strand incompletely covering and inhomogeneous coating. Surprisingly, by this arrangement of the dry lubricant, the lubricating effect can be improved or the Reibverschleiss be reduced, resulting in an increased life of the tension member.

However, in principle it is also possible to provide a homogeneously formed coating instead of an inhomogeneous structure of the coating.

To produce a flexible tension member of several tensile elements, in particular of wires and / or strands and / or strands, a dry lubricant, in particular a dry lubricant according to the invention, preferably applied to the tensile elements before joining the tensile elements. The dry lubricant is preferably sprayed onto the tensile elements in a fluid state. A fluid state in this context is understood to mean a flowable state of the dry lubricant. Specifically, the dry lubricant z. B. in the liquid state and / or be sprayed in the form of an aerosol. In this context, an aerosol is understood as meaning a mixture of a gas, in particular air, and powder particles of the dry lubricant dispersed therein.

The spraying of the dry lubricant on the tensile elements of the tension member offers significant advantages compared to a conventional immersion coating with liquid lubricants. Thus, in particular, the amount of dry lubricant to be applied can be controlled in a wide range and in a simple manner, for example by regulating the strength and / or the duration of a spray jet. Also, when spraying the dry lubricant, no wipers are needed for excess dry lubricant. Since spraying can generally be relatively strongly focused and directed with respect to the propagation direction, spraying can additionally reduce the consumption of dry lubricant.

In a preferred variant, the dry lubricant is sprayed in the liquid state in the form of individual droplets on the tensile elements, wherein the tensile elements have a temperature below a melting temperature of the dry lubricant. The individual droplets of the dry lubricant are still liquid when hitting the tensile elements, but solidify due to the temperature of the tensile individual elements, which are below the melting temperature of the dry lubricant, within a short time, especially within fractions of a second. By spraying the dry lubricant in the liquid state and in the form of individual droplets, in particular, an extremely good adhesion of the dry lubricant to the tensile individual elements is achieved, as has already been described above. Furthermore, this makes it possible to form an incompletely covering and inhomogeneous coating, which, as explained above, can improve the lubricating effect of the dry lubricant.

But it is also possible to spray the dry lubricant on tensile elements having a temperature in the range of the melting point of dry lubricant or more. In this case, solidification of the sprayed dry lubricant may be initiated at a later time. Thus, under certain circumstances, the adhesion can be improved and the coating of the tensile elements by the dry lubricant is homogeneous.

In a further preferred variant, the dry lubricant is sprayed onto the tensile elements as an aerosol which contains solid powder particles of the dry lubricant. The tensile elements are heated before spraying, in particular up to a temperature which is above a melting point of the dry lubricant. To generate an aerosol z. B. powder particles of the dry lubricant in a coating chamber with an upward gas flow, in particular an air stream, swirled and thus be placed in a fluidized state. In the coating chamber thereby forms a proper Fluidized bed or a fluidized bed. The individual elements which are to be coated can then be moved, for example, through the coating chamber so that the powder particles contained in the aerosol strike the tensile elements to be coated. Due to the temperature of the tensile individual elements, which are above the melting point of the dry lubricant, melt the powder particles of the dry lubricant on the surfaces of the tensile elements and adhere.

The spraying of the dry lubricant in the form of an aerosol with solid powder particles on heated tensile elements is extremely efficient. The dry lubricant remains essentially only adhere to the tensile elements. On the boundary surfaces or walls of the coating chamber, which are usually not heated, the powdered dry lubricant is merely scattered, but does not adhere. This is virtually no dry lubricant lost, which is very economical.

In principle, it is also conceivable to produce an aerosol with liquid droplets of dry lubricant and z. B. deposit in an analogous manner in the coating chamber on the tensile elements. In this case, can be dispensed with heating of the tensile elements. However, some of the dry lubricant deposits on the usually cool walls of the coating chamber, which is less economical.

The individual tensile elements are preferably moved past a stationary spraying device and / or moved through a coating chamber. As a result, even very long tensile individual elements can be provided with limited space in a simple manner with dry lubricant. The tensile elements, z. As metal wires, can be unwound, for example, continuously with a take-off from a roll, past the stationary Aufsprühvorrichtung and / or through a coating chamber and then formed into a flexible and deflectable tension member, which in turn is wound onto a take-up roll. The tensile elements are stranded in particular after spraying the dry lubricant.

As Aufsprühvorrichtung for spraying liquid dry lubricant z. B. a per se known and operated with compressed air spray gun can be provided with an upstream melting device for the dry lubricant.

However, it is also within the scope of the invention to use a movable Aufsprühvorrichtung, which is at least partially moved during the spraying on the individual tensile elements along.

From the following detailed description and the totality of the claims, further advantageous embodiments and feature combinations of the invention result.

Brief description of the drawings

The drawings used to explain the embodiment show:

Fig. 1 is a side view of a first production line for spraying dry lubricant on individual elements of traction elements;

Fig. 2 is a cross-section along the line A - B of Fig. 1, which a

Single element before spraying with dry lubricant shows;

Fig. 3 is a cross-section along the line C - D of Fig. 1, which with the

Dry lubricant particles coated single elements before stranding shows;

Fig. 4 is a cross-section along the line E - F of Fig. 1, which is a stranded

Strand of single elements coated with dry lubricant particles shows;

5 shows a cross section through a sheathed traction cable, consisting of six stranded around the strand of Figure 4 stranded outer strands. Fig. 6 is a longitudinal section through a second production line with a through a

Induction heating and a metal strand filled with an aerosol;

Fig. 7 is a cross-section taken along line G-H of Fig. 6 showing the still unsprayed metal strand prior to entry into the coating chamber;

Fig. 8 is a cross-section along the line I - J of Fig. 6, which with the

Dry lubricant particles coated metal strand after emerging from the coating chamber shows.

Basically, the same parts are provided with the same reference numerals in the figures.

Ways to carry out the invention

1 shows a first production line 100 for the spraying of individual elements of tension members according to the invention. The first production line 100 has a rotatable unwinding device 101, shown on the left side in FIG. 1, out of which, spatially separated, a total of seven individual elements in the form of seven metal wires 1.1, 1.2,. The seven metal wires 1.1, 1.2, ... 1.7 are thereby tapered tapered into a forming tool 105, passed into it. In the forming tool 105, the seven metal wires 1.1, 1.2,... 1.7 are stranded in a known manner to form a first strand 10.1 with a rotating unwinding device 101. A caterpillar drive 106 downstream of the forming tool 105 pulls the first strand 10.1 out of the forming tool 105. After the caterpillar drive 106, a receiving roller 107 is further arranged, on which the first strand 10.1 is wound.

In a region between the rotatable Abspulgerät 101 and the forming tool 105 is above the seven metal wires 1.1, 1.2, ... 1.7 arranged a compressed air spray gun 104 as Aufsprühvorrichtung stationary. The spray gun 104 produces a widening and conical spray jet 51 of a molten or liquefied solid lubricant 50. The spray jet 51 consists of a plurality of droplets of the liquefied dry lubricant 50th Das Dry lubricant 50 is conveyed in the solid state via a supply line 103 from a reservoir 102 into the spray gun 104 and liquefied there by a not shown in FIG. 1 heater and then expelled by the compressed air in the form of the conical spray jet 51 from the spray gun 104.

The spray jet 51 of liquefied dry lubricant 50 is aligned and dimensioned such that the individual elements or the seven metal wires 1.1, 1.2,... 1.7 are all moved through the spray jet 51 while the first production line 100 is running. The individual elements to be sprayed are thus moved past the stationary spraying device or the spray gun 104. Due to the rotating Abspulgeräts 101 all seven metal wires 1.1, 1.2, ... 1.7 wetted from different sides of the spray jet 51 or present in the spray jet 51 droplets of liquefied dry lubricant 50 meet all sides of the lateral surfaces or surfaces of the seven through the spray through moved metal wires 1.1, 1.2, ... 1.7 on.

The dry lubricant 50 itself has, regardless of the state of aggregation, z. Example, the following composition:

The polyolefin-based thermoplastic hot-melt adhesive used, for example, has a density of 0.87 ± 0.03 g / cm ³ at 23 ° C., a softening point of 71 ± 5 ° C and at 80 ° C, a melt viscosity of 130 ± 25 mPa-s. In principle, however, hot melt adhesives made from other polymers with different densities and / or melt viscosities can also be used.

The polymer material in the form of low-density polyethylene (LDPE) of the dry lubricant 50 has, for example, a density of about 0.92 g / cm ³ , a melting temperature of about 1 10 ⁰ C, a melt flow index of about 21.0 g / 10 min (at a test temperature from 190 ⁰ C and a test load of 2.16 kg) and a Shore hardness about 40 Shore-D.

The synthetic wax in the dry lubricant 50 is z. Example, an amide wax of a Fettsäureamidester having a melting point of about 70 ⁰ C, a density of about 1.0 g / cm ³ and an acid value 0.025 mg KOH / g.

FIG. 2 shows a cross section through the seventh metal wire 1.7 from FIG. 1 along the line A-B. In this area of the first production line 100, which lies in front of the spray gun 104 or in front of the spray jet 51, the seventh metal wire 1.7, like the other six metal wires 1.1, 1.2,... 1.6, is not yet coated with dry lubricant 50. The cross-sectional area of the seventh metal wire 1.7 shown in FIG. 2 and the cross-sectional areas of the remaining six metal wires 1.1, 1.2,... 1.6 are circular.

FIG. 3 shows a cross section through the production line 100 along the line C - D. The line C - D in Fig. 1 is outside the range of the spray jet 51 and directly in front of the forming tool 105. In Fig. 3, the seventh metal wire 1.7 is arranged centrally, while the remaining six metal wires 1.1, 1.2, ... 1.6 mutually and spaced apart from the seventh metal wire 1.7 in a regular hexagon around the seventh metal wire 1.7. Individual and solidified dry lubricant particles 52 are present on all lateral surfaces or surfaces of the seven metal wires 1.1, 1.2,. The solidified dry lubricant particles 52 form an at least partially interrupted and inhomogeneous coating on the lateral surfaces of the seven metal wires 1.1, 1.2,... 1.7. The dry lubricant particles 52 on the seven metal wires 1.1, 1.2, ... 1.7 were out the droplets of liquefied dry lubricant 50, which were sprayed with the spray gun 104, obtained by cooling and solidification on the lateral surfaces of the metal wires 1.1, 1.2, ... 1.7.

The dry lubricant particles 52 also have substantially the same composition as the droplets of liquid dry lubricant 50 in the spray jet 51.

Fig. 4 shows a cross section along the line E - F in Fig. 1 by the first strand 10.1 and the seven metal wires 1.1, 1.2, ... 1.7 in a stranded state. The dry lubricant particles 52 arranged on the lateral surfaces of the seven metal wires 1.1, 1.2,... 1.7 keep all seven metal wires 1.1, 1.2,. There is therefore essentially no direct contact between the individual metal wires 1.1, 1.2,. The minimum distance between the seven metal wires 1.1, 1.2, ... 1.7 is, for example, 0.1 mm.

Fig. 5 shows a cross section through a sheathed traction cable 12, which is provided for example as an elevator rope and z. B. have a diameter of 5.0 mm. The

Pulling cable has the first strand 10.1 from FIGS. 1 and 4 as a core strand. Around the first strand 10.1 around another six strands 10.2, 10.3, ... 10.7 or outer strands are stranded in a regular arrangement. The other six strands 10.2, 10.3, ... 10.7 form an outermost layer of outer strands. Each of the further six strands 10.2, 10.3,... 10.7 consists of seven wires or individual elements, which are essentially identical, such as the seven metal wires 1.1, 1.2,... 1.7 of the first strand

10.1. In contrast to the first strand 10.1, the wires of the further six strands 10.2,

10.2, ... 10.7 but not coated with dry lubricant particles 52. Thus, the outer surfaces of the further six strands 10.2, 10.3,... 10.7 or the surface regions of the further six strands 10.2, 10.3,..., 10.7 which are not in contact with the first strands 10.1 are completely free of dry lubricant. In other words, therefore, an outer surface of the outermost layer of outer strands is free of dry lubricant. The other six strands 10.2, 10.3,... 10.7 were also produced on the first production line 100 when the spray gun 104 was switched off. To the other six strands 10.2, 10.3, ... 10.7 or around the outermost layer of outer strands around an extruded sheath 1 1 is further arranged polyurethane. The cable sheath 1 1 surrounds the outermost layer of outer strands completely and is partially formed on this. Also between the cable sheath 1 1 and the outermost layer of outer strands no dry lubricant is arranged.

The mass of the dry lubricant particles 52 arranged in the sheathed traction cable 12 is, for example, about 100 mg per linear meter of the traction cable 12. With a diameter of the traction element 12 of about 5.0 mm, the surface density of the dry lubricant or the dry lubricant particles 52 is based on the outermost lateral surface or the outer surface of the cable sheath 1 1 thus about 6.4 g / m ² .

FIG. 6 shows a detail view of a second production line 200 for the production of tension members according to the invention in longitudinal section. The second production line 200 is essentially identical to the first production line 100 from FIG. 1, but has neither a spray gun 104 with supply line 103 nor a storage container 102. Instead, in the second production line 200 between the forming tool and the track drive, an induction heater 201 and a stationary coating chamber 202.

When the second production line 200 is running, a metal wire 20 guided out of the forming tool is passed through the induction heater 201. In the induction heating 201, the metal strand 20 is heated by inductive heating in a conventional manner. The heated metal wire 20 then passes through an inlet opening 202.1 of the coating chamber 202 into an inner cavity 202.3 of the coating chamber 202. The metal wire 20 coated in the coating chamber 202 is led out of the inner cavity 202.3 of the coating chamber 202 through an exit opening 202.2 of the coating chamber 202.

In the inner cavity 202.3 of the coating chamber 202, there is an aerosol of solid powder particles 60 of dry lubricant in air 61. The air 61 is thereby continuously by a fan, not shown in Fig. 6, which generates an air flow in the inner cavity 202.3 of the coating chamber 202 is circulated so that the solid powder particles 60 are dynamically suspended in the dry lubricant. The powder particles 60 of dry lubricant are distributed substantially statistically in the interior of the cavity 202.3.

The powder particles 60 of dry lubricant melt when hitting the heated metal strand 20 and adhere to the outer surface of the metal strand 20. After the metal strand 20 has left the coating chamber 202, it cools down to such an extent that the powder particles 60 of dry lubricant adhering and liquefied on the outer surface of the metal strand 20 rapidly solidify.

FIG. 7 shows a cross section through the metal strand 20 along the line G - H from FIG. 6. The line G - H lies in a region between the induction heating 201 and the coating chamber 202. The metal strand 20 consists of a core wire 2.7 and six outer wires 2.1, 2.2, ..., 2.6 stranded around it. The core wire 2.7, as well as the outer wires 2.1, 2.2, ..., 2.6 all have a circular cross-sectional area of the same size.

8 shows a cross section through the metal strand 20 along the line I-J from FIG. 6. The line I-J lies in a region downstream of the output opening 202. 2 of the coating chamber 202. The outer surface areas of the outer wires 2.1, 2.2, ..., 2.6 of the metal strand 20 are covered with individual and solidified dry lubricant particles 62. The solidified dry lubricant particles 62 form an at least partially discontinuous and inhomogeneous coating on the outer surface areas of the outer wires 2.1, 2.2,..., 2.6. The core wire 2.7 is accordingly completely free of dry lubricant particles.

The dry lubricant powder particles 60 as well as the dry lubricant particles 62 on the metal strand 20 have, for example, the same composition as the dry lubricant 50 described in FIG.

Test experiments have shown that the life of the tension member of FIG. 5, which has a core strand or first strand 10.1 provided with dry lubricant particles 52, is greater by at least a factor of 1.5-2 than the lifetime of an element Essentially identical tension member, which however has a Kemlitze without dry lubricant particles.

Furthermore, it has been found that the tension member of FIG. 5 with dry lubricant compared to the identical tension member, which has a core strand without dry lubricant particles, has no disadvantages when used in friction drives. The maximum transferable tensile force is essentially identical for both tension members over the entire service life.

The exemplary embodiments described above are only to be understood as illustrative examples, which can be modified as desired within the scope of the invention.

Thus, with the first production line 100 shown in FIG. 1, it is basically also possible to strand more or less than seven metal wires 1.1, 1.2,... 1.7 into a stranded wire. In this case, metal wires with a different cross section, which z. B. oval or trapezoidal are used. Likewise, it is conceivable to use non-metallic individual elements instead of the metal wires 1.1, 1.2,. These can be z. B. consist of tensile fibers. Also possible is the combined use of metallic and non-metallic individual elements. Accordingly, the individual elements and strands shown in FIGS. 2-4 have other cross sections.

Likewise, in the first production line 100, the spraying device or the spray gun 104 can be arranged in a region between the forming tool 105 and the crawler drive 106. In particular, the already stranded first strand 10.1 can be sprayed from the outside.

The Aufsprühvorrichtung or the spray gun 104 may also be designed to be movable, so that they surround the individual elements to be sprayed, z. B. the metal wires 1.1, 1.2, ... 1.7 and / or strands to move around. This may be particularly useful for homogeneous spraying.

The traction cable 12 shown in FIG. 5 can furthermore also be designed without a cable jacket 1 1. Furthermore, it may be advantageous, the respective innermost or central Single element of the other six strands 10.2, 10.3, ... 10.7 or external strands to spray during manufacture with dry lubricant. As a result, the life of the cable may be extended further under certain circumstances. Likewise, the pull rope 12 may also have additional and / or differently designed strands or outer strands. Also possible is the combination of non-metallic and metallic strands in the pull rope or the replacement of a metallic single element in a strand through a non-metallic single element.

It is also basically within the scope of the invention, in the pull rope 12 shown in FIG. 5, to provide intermediate sheaths around inner strands and / or strand layers and / or to form the sheath 1 1 in a multilayered manner. It is also possible to structure the rope sheath to increase the friction in friction drives.

In the illustrated in Fig. 6 second production line 200, for example, the induction heater 201 by another heating device, such. As an infrared source to be replaced. In this case, it is also possible in principle to coat non-metallic strands and / or individual elements in the second production line 200 with dry lubricant particles, provided that the non-metallic strands and / or individual elements can be sufficiently heated.

Also, with the second production line, individual elements, in particular metallic wires, can be coated with dry lubricant particles. The coated wires can then z. B. to a strand as shown in Fig. 4 is stranded.

For the formation of homogeneous coatings of dry lubricant, for example, the amount of liquefied solid lubricant 50 sprayed per time can be increased in the first production line 100, resulting in complete wetting of the individual elements 1.1, 1.2,. Accordingly, in the second production line 200, the density of the powder particles 62 of dry lubricant in the aerosol can be increased, resulting in complete wetting of the surface of the metal strand 20. The dry lubricant 50 mentioned in connection with FIG. 1 may also contain ethylene vinyl acetate as polymer material instead of or in addition to the low density polyethylene (LDPE). The ethylene vinyl acetate may, for. B. a density of 0.95 g / cm ³ , a melting temperature of about 80 ⁰ C, a melt flow index of about 20.0 g / 10 min (at a test temperature of 190 ⁰ C and a test load of 2.16 kg) and a Shore hardness of have about 35 Shore-D.

Instead of or in addition to the synthetic amide wax, the dry lubricant 50 may also comprise a polyethylene wax, for example having a melting point of 15 ° C, a density of 0.92 g / cm ³ and an acid value of 0.05 mg KOH / g.

The dry lubricant 50 may further contain an additional adhesion promoter, which may be in the form of, for example, an aminosilane having a density of e.g. B. 0.94 g / cm ³ , a boiling point of about 225 ° C and a flash point of about 95 ° C is present.

In summary, it should be noted that a novel dry lubricant was found, which can be used extremely economically and user-friendly in the manufacture of ropes. The dry lubricant can be further adapted to a variety of specific requirements by changing the composition in a relatively simple manner. Due to the nature of the dry lubricant, contamination and contamination of production lines can be greatly reduced, which in particular reduces the maintenance of the production lines. Tensile elements which contain the dry lubricant according to the invention furthermore have a multiple longer lifetime and high reliability. The dry lubricant remains relatively stationary throughout the life in the tension member and is not secreted in particular. Thus, the inventive dry lubricant allows the lubrication of traction devices, which are provided for friction drives and in particular have sheaths. The lubrication of such traction elements has been dispensed with until now for lack of a suitable lubricant usually.

Claims

claims

1. dry lubricant (50) for flexible tension members, in particular wire ropes and / or stranded cables for static and / or dynamic loads, characterized in that a major proportion of the dry lubricant consists of a polymer material.

2. dry lubricant (50) according to claim 1, characterized in that the

Polymer material is halogen-free.

3. dry lubricant (50) according to any one of claims 1-2, characterized in that the polymer material comprises a thermoplastic polymer having a melting point of at most 300 ⁰ C.

4. dry lubricant (50) according to claim 3, characterized in that the thermoplastic polymer comprises a polyolefin, wherein the polyolefin is in particular ethylene vinyl acetate and / or polyethylene and / or polypropylene.

5. dry lubricant (50) according to claim 4, characterized in that the polyolefin ethylene vinyl acetate having a density of 0.90 - 0.96 g / cm ³ and / or a

Melting temperature of 60 - 100 ⁰ C includes.

6. dry lubricant (50) according to any one of claims 4-5, characterized in that the ethylene vinyl acetate at a test temperature of 190 ° C and a test load of 2.16 kg a melt flow index of 1.0 - 43.0 g / 10min and / or a Shore hardness of 24-45 Shore-D.

7. dry lubricant (50) according to any one of claims 4-6, characterized in that the polyolefin includes polyethylene having a density of 0.90 - 0.94 g / cm ³ and / or a melting temperature of 100 - 120 ⁰ C.

8. dry lubricant (50) according to any one of claims 4-7, characterized in that the polyethylene at a test temperature of 190 ⁰ C and a test load of 2.16 kg, a melt flow index of 0.1 - 40.0 g / 10min and / or a Shore hardness of 20 - 60 Shore-D has.

9. dry lubricant (50) according to any one of claims 3-8, characterized in that the thermoplastic polymer comprises a polyester and / or a polyamide, wherein the polyester in particular to

Polybutylene terephthalate and / or polyethylene terephthalate is.

10. dry lubricant (50) according to any one of claims 3-9, characterized in that the thermoplastic polymer comprises a thermoplastic elastomer, in particular polyurethane and / or a thermoplastic polyester elastomer.

1 1. dry lubricant (50) according to any one of claims 3-10, characterized in that the thermoplastic polymer in the dry lubricant has a proportion of at least 50%, in particular at least 75%.

12. Dry lubricant (50) according to any one of claims 1-11, characterized in that the polymer material comprises a thermoset.

13. dry lubricant (50) according to any one of claims 1-12, characterized in that additionally a wax is contained, wherein the wax is preferably a synthetic polyethylene wax and / or a synthetic amide wax.

14. dry lubricant (50) according to claim 13, characterized in that a synthetic amide wax containing a Fettsäureamidester is present, preferably a melting point of the synthetic amide wax 50 - 80 ⁰ C and more preferably a density of the synthetic amide wax at 0.9 - 1.1 g / cm ³ lies.

15. Dry lubricant (50) according to any one of claims 13-14, characterized in that a polyethylene wax having a melting point of 105 - 120 ⁰ C and / or a density of 0.90 - 0.93 g / cm ³ is present.

16. Dry lubricant (50) according to any one of claims 1-15, characterized in that additional additives in the form of viscosity modifiers and / or antioxidants and / or corrosion inhibitors are containing.

17. dry lubricant (50) according to any one of claims 1-16, characterized in that in addition a thermoplastic hot melt adhesive is included.

18. dry lubricant (50) according to claim 17, characterized in that the thermoplastic hot melt adhesive has a polyolefin base.

19. dry lubricant (50) according to any one of claims 17-18, characterized in that the thermoplastic hot melt adhesive at a first temperature of 23 ° C has a density of 0.87 ± 0.03 g / cm ³ and that the thermoplastic hot melt adhesive has a softening point of at least 71 ± 5 ° C and that the thermoplastic hot melt adhesive at a second temperature of at least 80 ⁰ C has a melt viscosity of at least 130 + 25 mPa-s.

20. dry lubricant (50) according to any one of claims 17-19, characterized in that the thermoplastic hot melt adhesive forms a proportion of at least 1% and less than 50%.

21. dry lubricant (50) according to any one of claims 1-20, characterized in that an additional adhesion promoter in the form of an aminosilane, wherein preferably the aminosilane has a density of 0.90 - 0.97 g / cm ³ and / or a boiling point of 200 - 240 ⁰ C and / or has a flash point of more than 95 ° C.

22. A flexible tension member (12) for static and / or dynamic loads comprising a dry lubricant (50) according to any one of claims 1 - 21.

23. Flexible tension member (12) according to claim 22, comprising a core strand (10.1) and at least one surrounding the Kemstrang layer of outer strands (10.2, 10.3, ... 10.7), wherein the dry lubricant on a surface of tensile individual elements, in particular wires and / or strands and / or fibers of the core strand (10.1) are arranged.

24. A flexible tension member (12) according to any one of claims 22 - 23, characterized in that an outer surface of an outermost layer of outer strands of the flexible tension member (12) is free of dry lubricant.

25. Flexible tension member (12) according to any one of claims 22 - 24, characterized in that the arranged dry lubricant based on an outermost surface of the flexible tension member has a surface density of at least 1 g / m ² , wherein the surface density preferably at 1 - 20 g / m ² lies.

26. Flexible tension member (12) according to any one of claims 23 - 25, characterized in that the dry lubricant in the form of individual particles is present, wherein the individual particles form a surface of the tensile individual elements of the core strand (10.1) incompletely covering and inhomogeneous coating.

27. A method for producing a flexible tension member (12), in particular a flexible tension member according to one of claims 22 - 26, of a plurality of tensile elements

(1.1, 1.2, ... 1.7, 20), in particular wires and / or strands and / or strands, wherein prior to joining the tensile elements (1.1, 1.2, ... 1.7, 20) a dry lubricant (50), in particular a dry lubricant according to any one of claims 1-14, is applied to the tensile elements, characterized in that the dry lubricant (50) in a fluid state to the tensile elements (1.1, 1.2, ... 1.7, 20) is sprayed.

28. The method according to claim 27, characterized in that the

Dry lubricant (50) is sprayed in the liquid state in the form of individual droplets on the tensile elements (1.1, 1.2, ... 1.7), wherein the tensile elements (1.1, 1.2, ... 1.7) a temperature below a melting temperature of the

Dry lubricant (50).

29. The method according to claim 27, characterized in that the

An aerosol dry lubricant containing solid powder particles (60) of the dry lubricant to which tensile members (20) are sprayed, and wherein the tensile members (20) are heated prior to spraying, in particular up to a temperature above a melting point of the dry lubricant lies.

30. The method according to any one of claims 27 - 29, characterized in that the individual tensile elements (1.1, 1.2, ... 1.7, 20) on a stationary Aufsprühvorrichtung (104) over and / or through a coating chamber (202) passes therethrough become.

31. The method according to any one of claims 27 - 30, characterized in that the tensile elements (1.1, 1.2, ... 1.7) after the spraying of the dry lubricant (50) are stranded.

32. Use of a dry lubricant (50) according to any one of claims 1 - 21 in the manufacture of a flexible tension member (12) for static and / or dynamic

Loads.