Threaded connections and threaded connection fillers

Abstract

The present invention relates to a threaded connection (1) comprising: a female member (2) having a recess with an internal thread (4); a male member (5) having an external thread (6) configured to be disposed in a mating arrangement with the internal thread (4) of the female member (2); a thread tolerance between the external thread (6) of the male member (5) and the internal thread (4) of the female member (2); and a filler (7) configured to fill the thread tolerance, wherein the filler is a non-hardening, heterogeneous composition comprising a fluid carrier and solid particles suspended therein.

Description

[Technical Field]

[0001] The present invention relates to a threaded connection.

[0002] The invention further relates to a filler for a secure threaded connection and the use of said filler, as well as a method of applying or providing a threaded connection. [Background technology]

[0003] A conventional threaded connection may include a female member having a recess with internal threads, a male member having external threads configured to be disposed in a mating arrangement with the internal threads of the female member, a thread tolerance between the external threads of the male member and the internal threads of the female member, and a filler configured to fill the thread tolerance.

[0004] All threaded connections have thread tolerances because a certain amount of play is required between the male and female members to insert the external threads into the internal threads. This play is necessary for the threaded connection to work, but it can also be detrimental in certain applications.

[0005] For example, threaded connections can loosen over time due to play caused by thread tolerances, i.e., unscrewing. To prevent this, conventional thread locks, such as the commercially available Loctite® thread lock, were developed as fillers. Loctite® was developed to permanently lock all relatively small metal threaded connections. Thread lockers permanently secure and seal bolts, nuts, and studs, preventing loosening due to vibration. It is a methacrylate-based locking agent that permanently secures threaded connections to one part, preventing loosening of the nut and bolt due to vibration. Loctite® is uniformly distributed in the thread gap that defines the thread tolerance and hardens over time. Once hardened, Loctite® becomes a strong, solid medium that must be broken to remove the threaded connection, providing a threshold for unwanted loosening, i.e., unscrewing of the threaded connection. When a torque sufficient to break the solid medium is applied, it crumbles into pieces. Once broken, new Loctite® must be applied to restore a secure thread connection. However, because visual inspection of the media within the thread tolerances is not possible, there is a risk that failure or deterioration of the fastening properties of Loctite® will go unnoticed. Dynamic loading situations, such as bolted flanges in wind turbine structures or earthquakes, can cause the solid media of the thread lock to break, leading to failure over time if the security is insufficient to withstand future loads.

[0006] U.S. Patent No. 10,214,668 discloses an adhesive composition containing an epoxy resin, a binder, and a curing agent. This composition is useful for nuts and bolts that are typically placed on threaded surfaces. Like Loctite®, described above, this composition cures after application and suffers from similar drawbacks.

[0007] On the other hand, the play caused by thread tolerances can cause gas leakage through the thread tolerances. To prevent such gas leakage, gas tape can be applied as a filler. Gas tape fills the thread gap that defines the thread tolerance and is disposable. Eventually, the threads will cut the tape during the screwing operation, so new gas tape must be prepared after loosening the thread connection. Gas tape not only prevents leakage but also helps improve the thread connection.

[0008] A further disadvantage of thread locking and gas tape is that they are particularly suited to relatively small threaded connections. However, the bolted flanges mentioned above in wind turbine construction may apply bolted connections with nut sizes of M72 or larger. As a result, the gaps in the threads that must be filled with filler are also large, making traditional fillers such as the hardened thread locking and gas tape mentioned above less suitable for these applications. Summary of the Invention [Problem to be solved by the invention]

[0009] It is an object of the present invention to provide a threaded connection, a filler, and a use of the filler for a secure threaded connection that is an improvement over the prior art and in which at least one of the above-mentioned problems is avoided or mitigated. In particular, there is a need for a secure threaded connection that is suitable for relatively large connections and that can reliably withstand dynamic load conditions. [Means for solving the problem]

[0010] Said object is achieved by a threaded connection according to claim 1 of the present invention, which comprises: - a female element having a recess with an internal thread; a male member having an external thread configured to be placed in a mating arrangement with the internal thread of the female member; -Thread tolerance between the external thread of the male part and the internal thread of the female part; - Filler configured to fill thread tolerances; Including, Fillers are non-hardening heterogeneous compositions that include a fluid carrier and solid particles suspended therein.

[0011] The filler's heterogeneous composition includes a fluid carrier, such as a grease, that distributes and fills the thread tolerances. Unlike conventional thread locks, such as the commercially available Loctite® described above, the filler's fluid carrier remains fluid, i.e., does not harden, allowing the threaded connection to be repeatedly tightened (i.e., tightened) and released (i.e., loosened) without the need to replace the filler. The fluid carrier defines a carrier for the solid particles suspended within the fluid carrier, and as a result, these suspended solid particles are also dispersed throughout the thread gap and define the thread tolerance. When the threaded connection is tightened and a pretensioning torque is applied, the external thread of the male component and the internal thread of the female component move relative to each other in the longitudinal direction of the male component. As a result, the thread tolerance becomes asymmetrical relative to the thread. More specifically, the pretensioning force forces the internal and external threads against each other, thereby locally reducing the thread tolerance between the internal and external threads. As a result, the thread tolerance must be increased in other locations. The locally reduced thread tolerances ensure that solid particles suspended in the filler cannot easily pass through these narrow thread gaps, and as a result, the pretensioned threaded connection can withstand high, repeated dynamic loads. However, due to the fluidity of the fluid carrier in the filler, the threaded connection can be loosened and reused many times.

[0012] In summary, the present invention provides a threaded connection that can be easily applied to relatively large threaded connections, can withstand high dynamic loads, and can be reused multiple times by applying a filler that is a non-hardening heterogeneous composition comprising a fluid carrier and solid particles suspended therein.

[0013] In contrast, curable compositions cure or solidify after application and then degrade over time, especially under dynamic loading conditions. The compression / decompression cycles of dynamic loading conditions can crush, abrade, or break down filler particles within the thread tolerances, while preventing filler particles from relocating within the thread tolerances during or after exposure to such dynamic conditions. This can potentially defeat the purpose of the particles, which is to reduce play. Furthermore, curable compositions require more complex formulations. In contrast, the non-curable heterogeneous compositions of the present invention can contain only a fluid carrier and solid particles.

[0014] Further advantages or inventive effects are achieved in accordance with the present disclosure by combining the features of the accompanying independent claims. Preferred embodiments are the subject of the dependent claims.

[0015] In the following description, preferred embodiments of the present invention will be further explained with reference to the drawings. [Brief explanation of the drawings]

[0016] [Figure 1] 1 to 4 are sequential schematic diagrams illustrating the application of a connection according to a first preferred embodiment. [Figure 2] 1 to 4 are sequential schematic diagrams illustrating the application of a connection according to a first preferred embodiment. [Figure 3] 1 to 4 are sequential schematic diagrams illustrating the application of a connection according to a first preferred embodiment. [Figure 4] 1 to 4 are sequential schematic diagrams illustrating the application of a connection according to a first preferred embodiment. [Figure 5] 5 to 7 are sequential schematic diagrams illustrating the application of a connection according to a second preferred embodiment of the present invention. [Figure 6] 5 to 7 are sequential schematic diagrams illustrating the application of a connection according to a second preferred embodiment of the present invention. [Figure 7] 5 to 7 are sequential schematic diagrams illustrating the application of a connection according to a second preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] In both embodiments, the threaded connection 1 includes a female member 2 having a recess 3 with internal threads 4, and a male member 5 having external threads 6 configured to be disposed in a mating arrangement with the internal threads 4 of the female member 2. Further, a thread tolerance T is provided between the external threads 6 of the male member 5 and the internal threads 4 of the female member 2. The threaded connection 1 further includes a filler 7 configured to fill the thread tolerance T, the filler 7 being a non-hardening, heterogeneous composition including a fluid carrier 8 and solid particles 9 suspended therein.

[0018] The thread tolerance T is defined as the difference in diameter between the outer diameter φF of the female part and the outer diameter φM of the male part: T = φF - φM. Because the thread tolerance T is calculated by the difference in diameter, that size is distributed to the opposite side, resulting in a distance of T / 2 on each side.

[0019] The thread tolerance T results in a thread gap G, which is defined as the distance perpendicular to the facing faces 10, 11 of the internal thread 4 of the female part 2 and the external thread 6 of the male part 5 (FIG. 7). The size of the thread gap G can vary depending on the pretensioning force applied to the threaded connection, as will be explained in more detail below with reference to the detailed view of FIG. 7.

[0020] In the first preferred embodiment shown in Figures 1-4, the threaded connection 1 includes a single male member 5 that is threaded into a recess 3 having a bottom 12 containing a filler 7. Figure 2 shows the situation where the male member 5 is already partially threaded into the female member 2. In Figure 3, the male member 5 is further threaded into the female member 2, with the end face 13 of the male member 5 contacting the filler 7 on the bottom 12. The threading action of the male member 5 (indicated by arrow R) forces the filler 7 to distribute into the decreasing volume between the bottom 12 of the female member 2 and the end face 13 of the male member, thereby forcing the filler 7 into the thread gap G created by the thread tolerance T. Figure 4 shows the final situation, where the end face 13 of the male member 5 is in intimate contact with the bottom 12 of the female member 2, thereby forming the pretensioned threaded connection 1 and allowing the filler 7 to perform its desired function. This function of the filler 7 will be explained in more detail with reference to the second preferred embodiment.

[0021] The second preferred embodiment, shown in Figures 5-7, is closely related to the first preferred embodiment. Similar reference numerals are used for similar features. The primary difference from the first preferred embodiment is that the female member 2 is a coupler 14 with a recess 3, which is a threaded through-hole 15. This embodiment lacks a bottom 12, but instead is designed to receive and couple two male members 5a, 5b, each of which includes respective end faces 13a, 13b. As the end faces 13a, 13b of the male members 5a, 5b are threaded toward each other, the filler 7 disposed between these end faces 13a, 13b is forced to distribute within the decreasing volume between the end faces 13a, 13b of the male members 5a, 5b, as in the first preferred embodiment, thereby forcing the filler 7 into the thread gap G resulting from the thread tolerance T.

[0022] As previously mentioned, filler 7 is a non-hardening, heterogeneous composition comprising a fluid carrier 8 and solid particles 9 suspended therein. The detailed view in Figure 7 shows how the thread gap G is compressed on one side by the pretensioned thread connection 1 (indicated by the letter "c" for "compressed"). Compressed thread gap G ccreates resistance to the solid particles 9 of the filler 7 being forced into the narrow space between the opposing surfaces 10, 11, thereby securing the threaded connection 1 and allowing it to effectively withstand dynamic loading conditions, such as those caused by earthquakes. For example, the female member 2 may be a coupler 14 connecting mechanical rebars defining the male members 5a, 5b in critical buildings such as nuclear power plants. Of course, the invention is also applicable to other applications where loads are critical, such as in the oil and gas industry, among others. Other dynamic loads are also found in wind turbines.

[0023] However, because the filler 7 is a non-hardening, heterogeneous composition containing a fluid carrier 8 and solid particles 9 suspended therein, it can also easily degrade the threaded connection 1. Eventually, when the pretensioning force is removed by loosening the threaded connection 1, the thread gap G is no longer compressed. This allows the thread gap G to be more evenly distributed, providing sufficient space for the solid particles 9 suspended within the fluid carrier 8 to move within the thread gap G. Because the filler 7 is a non-hardening, heterogeneous composition containing a fluid carrier 8 and solid particles 9, it does not require curing and can therefore degrade. Furthermore, in safety-critical applications, it can withstand dynamic loads multiple times. This contrasts with traditional thread locks (e.g., Loctite®), which can harden and fail under load; this failure may remain unnoticed, potentially resulting in insufficient resistance to future dynamic loads.

[0024] The size of the solid particles 9 is preferably selected according to the thread tolerance T. Particle size can be measured using scattering techniques, such as light scattering. It has been found that solid particles 9 that are very small compared to the thread tolerance T only moderately reduce play, while solid particles 9 that are very large compared to the thread tolerance T prevent the filler 7 from flowing into the thread gap G. The solid particles 9 are preferably smaller than the thread tolerance T, although some (e.g., 10-20%) may be larger. A solid particle 9 with an average particle size in the range of 20-80% of the thread tolerance T provides an appropriate balance. The particle size distribution of the solid particles 9 is preferably such that the majority of the solid particles 9 fall within this range. A proportion of small and / or large solid particles 9 outside this range is acceptable and does not adversely affect the functionality of the filler 7 or the threaded connection 1. Appropriate particle size and particle size distribution can be achieved by known techniques, such as sizing and sieving.

[0025] In a further preferred embodiment, the solid particles 9 are s The powder size of the solid particles 9 is ≦T / 4. The size, in particular the average particle size, of the solid particles 9 can be in the range of 0.01 to 50% of the thread tolerance T, preferably in the range of 0.1 to 30% of the thread tolerance T. This size allows the filler 7 to be transported, for example under pressure, through the thread gap G between the internal thread 4 and the external thread 6, providing flexibility to fasten these threads 4, 6 by reducing play.

[0026] The size of the solid particles 9 ranges from 1 nm to 1000 μm, preferably from 10 nm to 100 μm, and more preferably from 0.1 to 50 μm. The filler 7 may contain solid particles 9 of various sizes, for example, by providing the solid particles 9 with a particle size distribution or by combining multiple particle sizes, each with a relatively narrow size distribution. This can accommodate local and / or temporal variations in the thread tolerance T of the threaded connection 1 during screwing or unscrewing. Advantageously, a wider range of particle sizes can be used, thereby broadening the range of applications of the filler 7. This is particularly advantageous when large screws are used, for example, for wind turbines or as threaded connections for mechanical reinforcing bars (i.e., reinforcing bars). Preferably, the solid particles 9 are more or less spherical.

[0027] In a further embodiment, the threaded connection 1 comprises a filler 7, which in turn comprises solid particles 9 made of an inorganic material.

[0028] In a further embodiment, the threaded connection 1 comprises a filler 7, which comprises solid particles 9 made of a non-corrosive material. This is advantageous because the non-corrosive solid particles 9 maintain their particle size better than corrosive particles, and the non-corrosive material generally does not cause corrosion of the female and male members 2, 5 of the threaded connection 1.

[0029] In a further embodiment, the solid particles 9 are oxides, carbides and / or sulfides of the group of alkali metals, alkaline earth metals, transition metals, basic metals and metalloids, preferably oxides or carbides of the group of alkali metals, alkaline earth metals, transition metals, basic metals and metalloids.

[0030] In a further embodiment, the solid particles 9 are selected from a group of materials including at least CaO, SiO2, TiO2, Al2O3, MgO, or graphene. SiO2 (i.e., silica) is preferably used. Additionally, cement powder can be used as a filler solid material. Cement is composed of calcium silicate, or at least CaO and SiO2. Cement is a binder—a construction substance that hardens, sets, glues, and binds other materials. Cement is rarely used alone; it is used to bind sand and gravel (aggregates). Cement is mixed with fine aggregate to make masonry mortar, and sand and gravel to make concrete. Concrete is the most widely used material in existence and is second only to water as the most consumed resource on Earth. Cement used in construction is typically inorganic and often based on lime or calcium silicate. Portland cement is by far the most common type of cement commonly used worldwide. This cement is typically made by heating limestone (calcium carbonate) with other materials (such as clay) in a kiln to 1,450°C (2,640°F). This process, called calcination, liberates carbon dioxide molecules from the calcium carbonate to form calcium oxide, or quicklime, which chemically combines with other materials in the mixture to form calcium silicate and other cement compounds. The resulting hard substance, called "clinker," is ground into a powder with a small amount of gypsum to create ordinary Portland cement, the most common type of cement. Portland cement is the basic ingredient in concrete, mortar, and most non-specialty grouts. The most common use of Portland cement is in the production of concrete, a composite material made of aggregates (gravel and sand), cement, and water. As a construction material, concrete can be molded into almost any shape and, once hardened, becomes a structural (load-bearing) element.

[0031] In a further embodiment, it is preferred to use cement as the particle source for filler 7, which comprises a non-setting heterogeneous composition comprising a fluid carrier 8 and solid particles 9 suspended therein.

[0032] The filler 7 is preferably formulated as a paste so that it remains within the female component 2 of the threaded connection prior to threading of the one or two male components 5, 5a, 5b. In a further embodiment, the fluid carrier 8 has a viscosity, particularly a kinematic viscosity, in the range of 100 to 4000 centistokes, preferably 150 to 400 centistokes, preferably at 20° C. This viscosity range is preferably maintained over a temperature range of −40° C. to +60° C., which covers most practical applications of the present invention.

[0033] The fluid carrier 8 comprises a grease. Examples include synthetic grease or mineral grease. Another example is the bearing grease or ball bearing lubricant commercially available under the names SuperHT or Arpol 9901. These are intended as bearing lubricants and exhibit low viscosity at high temperatures, but their viscoelastic properties at room temperature (e.g., in the temperature range of -40°C to +60°C) have been found to be highly suitable for application in the present invention.

[0034] As a practical example, the filler 7 may be composed of grease as the fluid carrier 8 and cement powder as the solid particles 9. When combining grease and cement powder, a weight ratio of 1:2 has proven effective, even without further additive components in such a filler 7. The fluid carrier 8, which is or includes grease, can also be combined with other solid particles 9 disclosed herein, or a combination of solid particles 9 can be used. In such cases, the weight ratio of fluid carrier 8 to solid particles 9 may still be 1:2. More typically, this ratio ranges from 1:0.5 to 1:5, preferably 1:1 to 1:3, and even more preferably 1:2. Coarser threads (i.e., larger thread tolerances T, typically larger thread pitches) may require a relatively higher amount of solid particles 9 relative to the fluid carrier 8, while finer threads may require a smaller amount of solid particles 9.

[0035] The screw connection 1 may be, for example, a mechanical rebar screw connection as part of a mechanical rebar connecting system.

[0036] The female member 2 of the threaded connection 1 may be a rebar coupler configured to connect at least one mechanical rebar defined by a male member 5, for example as described in relation to Figures 1-4. Additionally or alternatively, the female member 2 may be a rebar coupler configured to connect two mechanical rebars, each defined by a similar male member 5, for example as described in relation to two male members 5a, 5b in Figures 5-7.

[0037] The present invention also relates to a filler 7, particularly a threaded connection filler, comprising a non-curing heterogeneous composition comprising a fluid carrier 8 and solid particles 9 suspended therein. Preferably, the filler 7 comprises a grease having a viscosity of 100-4000 centistokes, more preferably 150-400 centistokes, and / or particles comprising at least CaO and SiO2. Any of the features disclosed above with respect to the filler 7 can also be used in the filler 7 separate from the threaded connection 1. The filler 7 can be provided in a container, such as a squeeze tube with a nozzle, for easy application to the components of the threaded connection 1.

[0038] The present invention also relates to the use of a filler 7 comprising a non-hardening heterogeneous composition including a fluid carrier 8 and solid particles 9 suspended therein to secure a threaded connection against dynamic loading conditions. The filler 7 is particularly suitable for relatively large connections and can be used in threaded connections and / or mechanical rebar connection systems that can reliably withstand dynamic loading conditions. Existing mechanical rebar connection systems can be improved in their ability to withstand dynamic loading conditions by applying the filler 7 to one or more thread tolerances T present in the threaded connections 1 of such systems.

[0039] It is contemplated that the female member 2 may be provided with a filler 7 as a separate product located within a recess, which may be used to mechanically connect one or two rebars (e.g., male members 5a, 5b) during construction operations. That is, in any of the disclosed embodiments of the threaded connection 1, a female member 2 combined with a filler 7, but excluding the male member 5, is also disclosed.

[0040] A threaded connection 1, in particular a coupler for a mechanical rebar connecting system, in particular a rebar coupler, is provided, comprising: a female member 2 having a recess 3 with an internal thread 4 configured for mating arrangement with a male member 5, in particular an external thread 6 of a rebar, and exhibiting a thread tolerance T between the external thread 6 of the male member 5 and the internal thread 4 of the female member 2; and a filler 7 disposed within the recess 3 and configured to fill the thread tolerance T, the filler 7 being a non-hardening heterogeneous composition comprising a fluid carrier 8 and solid particles 9 suspended therein;

[0041] There is also provided a method for applying or providing a threaded connection 1 that is preferably secured against dynamic loading conditions, said method comprising: providing a female member 2 having a recess 3 with an internal thread 4; providing a male member 5 having an external thread 6 configured for mating arrangement with the internal thread 4 of the female member 2; providing a filler 7 configured to fill a thread tolerance T between the external thread 6 of the male member 5 and the internal thread 4 of the female member 2, wherein the filler 7 is a non-hardening heterogeneous composition comprising a fluid carrier 8 and solid particles 9 suspended therein; and - The external thread 6 of the male member 5 is mated with the internal thread 4 of the female member 2, and a filler 7 is placed between them to obtain a threaded connection 1.

[0042] The method may include providing a threaded connection 1 according to any of the embodiments disclosed herein and / or a filler 7 according to any of the embodiments disclosed herein. The threaded connection 1 obtained by this method may be secured against dynamic loading conditions.

[0043] Slip tests according to ISO standard 15835-2:2009 were carried out on various threaded connections in the form of mechanical rebar couplings (female member with two female members according to the second preferred embodiment described above). Slip was evaluated according to option 2 of ISO standard 15835-1:2009. Table 1 shows the test results for samples containing a filler according to the invention. Table 2 shows the test results for comparative samples without filler.

[0044] The filler for this particular test was grease mixed with cement powder in a 1:2 weight ratio. For the slip test, the samples were subjected to tensile force cycles from 0 MPa to 300 MPa, meeting 60% of the rebar's specified characteristic (or nominal) yield strength value, and then returned to 10 MPa, where slip was evaluated. To further evaluate repeated exposure to tensile forces, three consecutive cycles of slip tests were performed on Samples 2a-2f in Table 1. Samples 1a-1f were also tested.

[0045] Threaded connections using the filler of the present invention exhibit low slippage, meeting the stringent requirements of the above-mentioned standard, which requires a slippage of 0.10 mm or less. The larger the nominal diameter of the reinforcing bar (male member), the greater the slippage in conventional couplings, which typically do not meet the standard. The present invention provides a filler that can be used to reduce slippage in mechanical rebar couplings, thereby enabling rebar couplings with larger diameters (e.g., nominal diameters of 25 mm or more) to comply with the ISO standard. Furthermore, even after three repeated slip tests, the use of the filler resulted in slippage compliance with the standard, demonstrating that such couplings can withstand repeated exposure and dynamic loading.

[0046] [Table 1]

[0047] [Table 2]

[0048] The above-described embodiments, while showing preferred embodiments of the present invention, are intended to be merely illustrative of the present invention and in no way limit the scope of the present invention. Therefore, when reference signs are used after features recited in the appended claims, it should be understood that such signs are included only to enhance the understandability of the claims and in no way limit the scope of the claims. Furthermore, it should be particularly noted that those skilled in the art can combine the technical measures of different embodiments. The scope of protection is defined solely by the following claims.

[0049] The following reference symbols are used in the text: [Explanation of symbols]

[0050] 1 Threaded connection 2 female parts 3 recess 4 internal threads 5, 5a, 5b Male members 6 external threads 7. Filler 8 Fluid Carrier 9 solid particles 10, 11 Opposite surfaces 12 Bottom 13, 13a, 13b end face 14 Coupler 15 Threaded through holes G thread gap G c Compression Screw Gap φF: outer diameter of female part φM: outer diameter of male member R screw-in operation T-thread tolerance

Claims

1. A threaded connection (1), - a female element (2) having a recess (3) with an internal thread (4); - a male member (5) having an external thread (6) configured to be arranged in a mating arrangement with the internal thread (4) of the female member (2); - the thread tolerance (T) between the external thread (6) of the male element (5) and the internal thread (4) of the female element (2); and a filler (7) configured to fill said thread tolerance (T); Including, Threaded connection (1), characterized in that said filler (7) is a non-hardening heterogeneous composition comprising a fluid carrier (8) and solid particles (9) suspended therein.

2. Threaded connection (1) according to claim 1, wherein the thread tolerance (T) is defined as the difference between the outer diameter (φF) of the female member and the outer diameter (φM) of the male member.

3. 3. The threaded connection (1) according to claim 1 or 2, wherein the size of the majority of the solid particles (9) is smaller than the thread tolerance (T), preferably the average particle size of the solid particles is in the range of 20-80% of the thread tolerance (T).

4. Threaded connection (1) according to any one or more of the preceding claims, wherein the size of said solid particles (9) is in the range of 1 nm to 1000 μm, preferably in the range of 10 nm to 100 μm.

5. Threaded connection (1) according to any one or more of the preceding claims, wherein said solid particles (9) are made from inorganic material.

6. Threaded connection (1) according to any one or more of the preceding claims, wherein said solid particles (9) are made of a non-corrosive material.

7. 7. The threaded connection (1) according to any one or more of the preceding claims, wherein the solid particles (9) are oxides, carbides and / or sulfides of the group of alkali metals, alkaline earth metals, transition metals, basic metals and semi-metals, preferably oxides or carbides of the group of alkali metals, alkaline earth metals, transition metals, basic metals and semi-metals.

8. The solid particles (9) contain at least CaO, SiO 2 , TiO 2 , Al 2 O 3 Threaded connection (1) according to any one or more of the preceding claims, selected from the group of materials comprising: MgO, MgO or graphene.

9. Threaded connection (1) according to any one or more of the preceding claims, wherein the fluid carrier (8) has a viscosity in the range of 150 to 400 centistokes.

10. Threaded connection (1) according to any one or more of the preceding claims, wherein the fluid carrier (8) comprises grease.

11. Threaded connection (1) according to any one or more of the preceding claims, wherein the threaded connection is a mechanical rebar threaded connection.

12. Threaded connection (1) according to any one or more of the preceding claims, wherein the female element (2) is a rebar coupler (14) configured to couple at least one mechanical rebar defined by the male element (5).

13. Threaded connection (1) according to any one or more of the preceding claims, wherein the female member (2) is a rebar coupler (14) configured to connect two mechanical rebars each defined by a similar male member (5a, 5b).

14. A female element (2, 14) of a screw connection (1) according to any one or more of claims 1 to 13, wherein the filler (7) is arranged in the recess (3) of the female element (2, 14).

15. A filler (7), particularly a threaded connection filler, configured to fill the thread tolerance (T) of a threaded connection (1), the filler (7) being a non-hardening heterogeneous composition comprising a fluid carrier (8) and solid particles (9) suspended therein.

16. The solid particles (9) are CaO and / or SiO 2 16. The filler (7) according to claim 15, comprising:

17. 17. The filler (7) according to claim 15 or 16, wherein the solid particles (9) comprise cement powder.

18. A filler (7) according to any one of claims 15 to 17, wherein the fluid carrier (8) comprises a grease having a viscosity of 100 to 4000 centistokes, preferably 150 to 400 centistokes.

19. Use of a filler (7) according to any one of claims 15 to 18 for securing a threaded connection (1) against dynamic loading conditions.

20. A method for applying or providing a threaded connection (1) that is preferably secured against dynamic loading conditions, said method comprising the steps of: - providing a female element (2) having a recess (3) with an internal thread (4); - providing a male member (5) having an external thread (6) configured for mating arrangement with the internal thread (4) of the female member (2); - providing a filler (7) configured to fill the thread tolerance (T) between the external thread (6) of the male member (5) and the internal thread (4) of the female member (2), wherein the filler (7) is a non-curable heterogeneous composition comprising a fluid carrier (8) and solid particles (9) suspended therein; and - placing said external thread (6) of said male part (5) in mating relation with said internal thread (4) of said female part (2) and placing said filler (7) therebetween to obtain said threaded connection (1); A method comprising:

21. A method according to claim 20, comprising providing a threaded connection (1) according to any one of claims 1 to 13 and / or a filler (7) according to any one of claims 15 to 18.

Images