Guidance unit for guiding a wire

Abstract

A guide unit for guiding a wire, comprising a guide roller (1) and at least one bearing (2) for rotatably mounting the guide roller (1) on a shaft (3), wherein the guide roller (1) is at least partially made of a martensitic steel material with an alloy composition comprising chromium, nitrogen and carbon, characterized in that the martensitic steel material has at least 14 wt.% to at most 16 wt.% chromium, at least 0.3 wt.% to at most 0.5 wt.% nitrogen and at least 0.25 wt.% to at most 0.35 wt.% carbon.

Description

[0001] The invention relates to a guide unit for guiding a wire, comprising a guide roller and at least one bearing for rotatably mounting the guide roller on a shaft. In particular, the guide unit can also guide a steel cable or other means.

[0002] In wire production, the wire to be rolled is guided in guide rollers, where high speeds and high forces occur. This causes wear not only on the bearings that allow the guide rollers to rotate, but also, and especially, on the guide rollers themselves, necessitating frequent replacement of these components.

[0003] For example, German patent DE 10 2010 046 611 A1 discloses a wire guiding unit comprising a wire guide roller rotatably mounted on a stationary shaft by means of a bearing, and a drive unit for the wire guide roller. The drive unit is designed as a rotor-stator unit, with the rotor attached to the wire guide roller. The rotor-stator unit can be controlled such that the rotational speed of the wire guide roller is adjusted so that no entry acceleration occurs when the wire enters the wire guide roller. This reduces the slippage between the wire and the wire guide roller, thereby simultaneously increasing the service life of the bearing and the wire guide roller.

[0004] The CN 1 04 789 872 A reveals a leading role.

[0005] A generic command unit is known from US 2019 / 0 185 976 A1.

[0006] The object of the present invention is to propose an alternative guide unit for guiding a wire. In particular, the service life of the guide unit is to be increased.

[0007] The problem is solved by the subject matter of claim 1 as well as by the subject matter of claim 2. Preferred embodiments are described in the dependent claims.

[0008] A first guide unit according to the invention for guiding a wire comprises a guide roller and (at least) a bearing for rotatably mounting the guide roller on a shaft, wherein the guide roller is at least partially made of a martensitic steel material with an alloy composition comprising chromium, nitrogen and carbon, and wherein the martensitic steel material has at least 14 wt.% to at most 16 wt.% chromium, at least 0.3 wt.% to at most 0.5 wt.% nitrogen and at least 0.25 wt.% to at most 0.35 wt.% carbon.

[0009] The preferred material is the martensitic steel X30CrMoN15-1. This material is also known as nitrogen-alloyed chromium steel under the material number 1.4108.

[0010] In particular, the martensitic steel material is an HNS steel (High Nitrogen Steel).

[0011] The alloy composition of martensitic steel can be determined, for example, by optical emission spectral analysis (OES) or X-ray fluorescence analysis (XRF). wt.% is the abbreviation for weight percent. In particular, the martensitic microstructure is achieved by controlled, rapid cooling after annealing or heat treatment. Preferably, the martensitic steel is also tempered.

[0012] A second guide unit according to the invention for guiding a wire comprises a guide roller and (at least) a bearing for rotatably mounting the guide roller on a shaft, wherein the guide roller is at least partially formed from a powder metallurgy composite material with a metallic binder phase and a hard phase, the metallic binder phase comprising at least chromium, cobalt, molybdenum, nickel and / or titanium, and the hard phase comprising at least borides, carbides, carbonitrides, nitrides and / or silicides. Such a powder metallurgy composite material is known from German patent application DE 10 2014 205 164 A1, in particular from paragraphs

[0004] to

[0047] , to which reference is made hereunder.

[0013] The hard phase has a proportion of 50-99 vol.% and in particular between 85 and 95 vol.%, and the metallic binder phase has a proportion of 1-50 vol.% and in particular between 5 and 15 vol.%.

[0014] The metallic bonding phase is based on at least one element from the group: chromium, cobalt, molybdenum, nickel, titanium. This means that the metallic bonding phase is formed from at least one element of the group: chromium, cobalt, molybdenum, nickel, titanium, or that it comprises at least one element of the group: chromium, cobalt, molybdenum, nickel, titanium as its main component. It also means that the metallic bonding phase is formed from, or comprises, a metallic compound containing chromium and / or cobalt and / or molybdenum and / or nickel and / or titanium. The elements mentioned can be present in their elemental form or in chemically bound compounds.

[0015] Powder metallurgy composite materials are generally characterized by a comparatively tough metallic binder phase and a comparatively hard hard phase. The toughness of the metallic binder phase compensates for the brittleness of the hard phase. The hardness of the hard phase gives the composite material its high hardness. Both the metallic binder phase and the hard phase are extremely corrosion-resistant. Powder metallurgy composite materials exhibit high strength, toughness, hardness, rolling resistance, and wear resistance, particularly against abrasion, adhesion, and cavitation, as well as high corrosion resistance.

[0016] The composite material from which the guide roller is at least partially, and in particular entirely, manufactured is produced using powder metallurgy processes, thus based on a powdered starting material or a powdered mixture of starting materials. The use of powder metallurgy processes is particularly advantageous because it enables the formation of microstructures with nearly isotropic properties. Likewise, the use of powder metallurgy processes generally allows for near-net-shape manufacturing or primary forming of the bearing element, which significantly reduces the need for mechanical, especially machining, post-processing steps and is therefore advantageous from a manufacturing and thus also economic perspective.In such a powder metallurgical process for manufacturing the bearing element, for example, hot isostatic pressing (HIP) can be used, according to which a powdered starting material or a powdered starting material mixture is compressed or pressed and sintered under pressure and temperature.

[0017] Another conceivable powder metallurgical process for manufacturing the guide roller is the spray compaction process, which is also a powder metallurgical manufacturing principle from the field of primary forming. According to this process, a powdered starting material or a powdered mixture of starting materials is sprayed onto a substrate, and a component is "built up" by layering it onto the substrate. One advantage of the spray compaction process compared to other powder metallurgical processes is that complete compaction of the powdered starting materials is not strictly necessary. A further advantage of the spray compaction process is the possibility of achieving a "tailor-made" material composition of the composite material, which can be formed with locally or spatially distributed material or concentration gradients.

[0018] In the context of the powder metallurgical production of the composite material, it is conceivable to combine the powdered material or material mixture forming the metallic binder phase with a powdered material or material mixture forming the hard phase using a powder metallurgical process. Alternatively, it is conceivable to first produce the metallic binder phase via a powder metallurgical process and then form the hard phase within the metallic binder phase through the subsequent targeted formation of precipitates, for example, during the initial forming of the composite material or a heat treatment.

[0019] The hard phase belonging to the powder metallurgy composite material is formed from or comprises at least one of the following hard compounds: borides, carbides, in particular titanium carbide and / or tungsten carbide, carbonitrides, in particular titanium carbonitride, nitrides, in particular titanium nitride, and silicides. The hard phase can therefore be formed from or comprise, in particular, hard metals, i.e., especially sintered carbide hard metals, such as tungsten carbide, and / or cermets, i.e., ceramic particles contained in a metallic matrix, e.g., based on nickel and / or molybdenum, such as titanium carbide, titanium carbonitride, or titanium nitride particles. Mixtures of (chemically) different hard compounds are also conceivable.

[0020] The two solutions according to the invention increase the wear resistance and hardness of the guide roller, with the first guide unit according to the invention being more cost-effective to manufacture than the second guide unit according to the invention. In contrast, the second guide unit according to the invention exhibits higher hardness and wear resistance compared to the first guide unit according to the invention.

[0021] According to a preferred embodiment of the invention, the bearing comprises an inner ring and rolling elements, wherein the inner ring is configured to be arranged on the shaft, and wherein a raceway for the rolling elements is formed on an inner circumferential surface of the guide roller. In other words, the rolling elements of the bearing roll between the inner ring and the inner circumferential surface of the guide roller. Thus, the bearing is designed as a direct bearing.

[0022] According to a further preferred embodiment of the invention, the bearing comprises an inner ring, an outer ring, and rolling elements, wherein the inner ring is configured to be arranged on the shaft, and wherein the outer ring is configured to be arranged on an inner circumferential surface of the guide roller. In other words, the rolling elements of the bearing roll between the inner ring and the outer ring.

[0023] Preferably, the inner ring is made of the same material as the guide roller. Therefore, the inner ring is either made of the martensitic steel material or the powder metallurgy composite material.

[0024] Preferably, the outer ring is made of the same material as the guide roller. Therefore, the outer ring is either made of the martensitic steel material or the powder metallurgy composite material.

[0025] Preferably, the rolling elements are made of a ceramic material or a steel alloy. In particular, the ceramic material is a high-performance ceramic. Preferably, the rolling elements are enclosed in a cage made of plastic, especially a high-performance plastic. Alternatively, the cage can also be made of a metal, especially a light metal alloy. For example, the cage is made of brass or a steel alloy.

[0026] Preferably, the metallic binder phase also contains at least some iron, carbon, and / or nitrogen. Thus, the metallic binder phase can additionally contain proportions of iron and / or carbon and / or nitrogen and / or at least one compound containing iron and / or carbon and / or nitrogen. This improves the bond between the metallic binder phase and the hard phase, which is typically formed from individual hard phase grains.

[0027] Further measures improving the invention are explained in more detail below, together with a description of a preferred embodiment of the invention, with reference to the single figure. The figure shows a highly simplified schematic sectional view of a guide unit according to the invention, shown in half.

[0028] The guide unit comprises a guide roller 1 with a groove 8 for receiving and guiding a wire (not shown) and a bearing 2 for rotatably mounting the guide roller 1 on a shaft 3. In this case, the shaft 3 is stationary and thus designed as an axle. The guide roller 1 is made of a martensitic steel material with at least 14 wt.% to at most 16 wt.% chromium, at least 0.3 wt.% to at most 0.5 wt.% nitrogen, and at least 0.25 wt.% to at most 0.35 wt.% carbon. The steel material used in this case is X30CrMoN 15-1. The groove 8 serves as a guide profile for the wire and is formed around the entire outer circumference of the guide roller 1.

[0029] Alternatively, the guide roller 1 can be formed from a powder metallurgy composite material comprising a metallic binder phase and a hard phase, wherein the metallic binder phase comprises at least chromium, cobalt, molybdenum, nickel, and / or titanium, and wherein the hard phase comprises at least borides, carbides, carbonitrides, nitrides, and / or silicides. Furthermore, the metallic binder phase can also include at least iron, carbon, and / or nitrogen. The hard phase can comprise 85–95 vol.% and the metallic binder phase 15–5 vol.%.

[0030] The bearing 2 comprises an inner ring 4, an outer ring 6, and a series of rolling elements 5. The inner ring 4 is arranged on the shaft 3. The outer ring 6 is arranged on an inner circumferential surface of the guide roller 1. The rolling elements 5 rotate between the inner ring 4 and the outer ring 6. In this case, the inner ring 4 and the outer ring 6 are made of the same material as the guide roller 1, namely X30CrMoN15-1. Furthermore, the rolling elements 5 are made of a steel alloy and guided in a plastic cage 7.

[0031] Alternatively, the outer ring 6 of the bearing 2 can be omitted, in which case the bearing 2 comprises only the inner ring 4 and the row of rolling elements 5. The inner ring 4 is then arranged on the shaft 3, and the rolling elements 5 bear directly against a raceway formed on an inner circumferential surface of the guide roller 1. The rolling elements 5 would then rotate between the inner ring 4 and the inner circumferential surface of the guide roller 1.

[0032] Furthermore, several bearings 2 can also be used for the rotatable mounting of the guide roller 1 on the shaft 3. For example, two bearings 2 or a double-row bearing 2 can be arranged for the rotatable mounting of the guide roller 1 on the shaft 3. Reference symbol list 1 Leadership role 2 warehouses 3rd wave 4 inner ring 5 rolling elements 6 outer ring 7 cage 8 Nut

Claims

[1] Guide unit for guiding a wire, comprising a guide roller (1) and at least one bearing (2) for rotatably mounting the guide roller (1) on a shaft (3), wherein the guide roller (1) is at least partially made of a martensitic steel material with an alloy composition comprising chromium, nitrogen and carbon, characterized by that the martensitic steel material contains at least 14 wt.% to at most 16 wt.% chromium, at least 0.3 wt.% to at most 0.5 wt.% nitrogen and at least 0.25 wt.% to at most 0.35 wt.% carbon. [2] Guide unit for guiding a wire, comprising a guide roller (1) and at least one bearing (2) for rotatably mounting the guide roller (1) on a shaft (3), wherein the guide roller (1) is at least partially formed from a powder metallurgy composite material with a metallic binder phase and a hard phase, the metallic binder phase comprising at least chromium, cobalt, molybdenum, nickel and / or titanium, and the hard phase comprising at least borides, carbides, carbonitrides, nitrides and / or silicides, characterized by , that the hard phase has a proportion of 50-99 vol.% and the metallic binder phase a proportion of 1-50 vol.%. [3] Guide unit according to claim 1 or 2, characterized by, that the bearing (2) comprises an inner ring (4) and rolling elements (5), wherein the inner ring (4) is arranged to be mounted on the shaft (3), and wherein a raceway for the rolling elements (5) is formed on an inner circumferential surface of the guide roller (1). [4] Guide unit according to claim 1 or 2, characterized by , that the bearing (2) comprises an inner ring (4), an outer ring (6) and rolling elements (5), wherein the inner ring (4) is arranged to be positioned on the shaft (3), and wherein the outer ring (6) is arranged to be positioned on an inner circumferential surface of the guide roller (1). [5] Guide unit according to claim 3 or 4, characterized by , that the inner ring (4) is made of the same material as the guide roller (1). [6] Guide unit according to claim 4, characterized by , that the outer ring (6) is made of the same material as the guide roller (1). [7] Guide unit according to claim 3 or 4, characterized by that the rolling elements (5) are made of a ceramic material or of a steel alloy. [8] Guide unit according to claim 2, characterized by that the metallic binding phase also contains at least some iron, carbon and / or nitrogen.

Images