Connection arrangement and method for manufacturing a sleeve-shaped connecting element

Abstract

Connection arrangement (1) connecting a first shaft (2) to a second shaft (3), wherein the end face (4) of the first shaft (2) and the end face (5) of the second shaft (3) are opposite or abutting each other, wherein both shafts (2, 3) are radially enclosed in their axial end region (6, 7) by a sleeve-shaped connecting element (8), wherein the sleeve-shaped connecting element (8) is arranged on the two shafts (2, 3) by a shrink fit, wherein the sleeve-shaped connecting element (8) is at least partially provided on its radially inwardly directed, cylindrical surface (9) with a friction-enhancing coating (10), wherein the friction-enhancing coating (10) comprises hard particles (11) which are formed by an electrolytically deposited metal layer (12) on the inwardly directed,cylindrical surface (9) of the connecting element (8) are fixed and wherein the hard particles (11) are diamond particles, boron nitride particles, silicon carbide particles or corundum particles.

Description

[0001] The invention relates to a connecting arrangement that connects a first corrugated component to a second corrugated component, wherein the end faces of the first corrugated component and the end faces of the second corrugated component are opposite or abutting each other, and wherein both corrugated components are radially enclosed in their axial end region by a sleeve-shaped connecting element, wherein the sleeve-shaped connecting element is at least partially provided with a friction-enhancing coating on its radially inwardly directed, cylindrical surface. The invention further relates to a method for manufacturing a sleeve-shaped connecting element.

[0002] In various technical applications, it is necessary to connect two shafts (solid shafts) or tubes (hollow shafts) by joining them end-to-end. A key requirement is that the connection between the shafts or tubes (generally referred to as wave-like components in the context of the present invention) is secure.

[0003] DE 89 15 961 U1 discloses a ring for forming catch nets, specifically for rockfall and sliding snow, wherein the ring ends are connected to each other via a crimp sleeve. This sleeve is lined internally with bonded quartz sand to increase friction. In this respect, the document presents the solution mentioned at the outset. DE 692 03 231 T2 discloses a method for hot-dip galvanizing, for which an electroplating process is used. Further solutions for the permanent connection of two parts are disclosed in DE 295 18 333 U1, DE 10 2005 043 238 A1, EP 1 538 381 A1, and DE 24 41 332 A1.

[0004] From DE 30 00 204 A1 a pipe coupling with a heat-resettable memory metal element is known, which, when reset, seals a plastically deformable element to the pipes, the inner surface of which is coated with a sealant in which a particulate filler, e.g. quartz, is dispersed.

[0005] From DE 10 2007 060 968 A1 a support roller with a bearing is known, wherein a damping layer is arranged between a ring of the bearing and the support roller, and a sleeve-shaped body is arranged between the support roller and the damping layer, which may be provided with a coating having friction-enhancing properties.

[0006] From DE 197 18 307 A1 a press connection is known, for which pressing surfaces are provided with a metal layer of high adhesion tendency, which leads to the formation of material connections in the form of cold press soldering connections or cold press welding connections when there are relative displacements between the pressing surfaces.

[0007] The invention is based on the objective of further developing a connection arrangement of the aforementioned type in such a way that a firm connection of the wave-shaped components to be joined together is possible using simple means.

[0008] The solution to this problem by the invention provides for items according to claims 1 and 2.

[0009] The two corrugated components preferably have the same outer diameter. The electrolytically deposited metal layer is preferably a nickel layer. The friction-enhancing coating in the form of a zinc or molybdenum layer (with or without hard particles) can be applied by plasma spraying or flame spraying.

[0010] The thickness of the friction-enhancing coating is usually less than 0.5 mm. A particularly preferred thickness range is less than 0.2 mm. The surface roughness (R) aThe surface roughness of the friction-enhancing coating preferably has a value of at least 15 µm, and particularly preferably a value of at least 20 µm. However, it should be noted that the surface roughness depends very strongly on the coating process and the stated value can therefore vary considerably.

[0011] The connecting element is preferably arranged on the two wave-shaped components by means of a shrink fit. The radial joining of components that have a tight fit or a transition fit can only be achieved within a certain tolerance range. Therefore, "shrink fit" here refers to a customized shrink fit.

[0012] The method for manufacturing a sleeve-shaped connecting element, which is provided with a friction-enhancing coating on its radially inwardly directed, cylindrical surface, is characterized according to the invention by the following steps: a) sealing the end faces of the connecting element on both sides with cover elements, so that a liquid-tight space is created; b) Inserting at least one anode and filling the space with an electrolyte containing hard particles; c) Applying a DC voltage between the connecting element and the at least one anode until a layer of desired thickness consisting of the material of the anode has galvanically bonded to the radially inwardly directed cylindrical surface, whereby - in order to achieve a uniform friction-enhancing coating - it is provided that the space is only partially filled with electrolyte and that the connecting element is rotated during step c).

[0013] According to the invention, the connecting element is provided with a friction-enhancing coating on its radially inwardly facing seating surface on the two corrugated components. This coating ensures a particularly firm hold of the connecting element on the corrugated component.

[0014] Thermal shrink-fitting has proven particularly effective as a mounting method for the connecting element onto the corrugated components. In this process, the component with the larger diameter (i.e., the connecting element) can be heated and then applied; alternatively or additionally, the component with the smaller diameter (i.e., the corrugated components) can be cooled and then the connecting element applied. After temperature equalization, a solid bond under radial tension is formed. The application of the friction-enhancing coating can also be carried out, for example, by spraying using a spray robot.

[0015] The proposed design ensures a secure fit of the connecting element on the corrugated components, even with large diameters. The friction-enhancing coating causes the particles to interlock with the mating surface, particularly when using hard particles, resulting in a micro-interlock.

[0016] The drawing shows an embodiment of the invention. It depicts: Fig. 1 in radial section a connection arrangement in which two wave-shaped components are connected to each other with a connecting element, Fig. 2 the detail “Z” according to Fig. 1, where only the connecting element including the friction-enhancing coating is shown, and Fig. 3 a connecting element which is received in a device which produces a friction-enhancing coating on the radially inwardly directed surface of the connecting element.

[0017] In Fig. Figure 1 shows a connection arrangement 1 comprising two corrugated components 2 and 3, which are rigidly connected to each other by a connecting element 8. The corrugated component 2 has an end face 4 in its axial end region 6, and the corrugated component 3 has an end face 5 in its axial end region 7.

[0018] The axial end regions 6, 7 of the corrugated components 2, 3 are radially encompassed by a connecting element 8. The connecting element 8 was joined to the two corrugated components 2, 3 using shrink-fit technology; that is, after heating the connecting element 8 and / or cooling the corrugated components 2, 3, the connection was formed. Fig. 1. The components are joined in the sketched position; after temperature equalization, a solid bond exists between the connecting element 8 and the respective component 2, 3.

[0019] Since the two corrugated components 2 and 3 have the same outer diameter D, the connecting element 8 is designed as a sleeve with a constant wall thickness and constant radius. If components 2 and 3 have different outer diameters, the geometry of the connecting element 8 must be adjusted accordingly.

[0020] To ensure a secure connection between the connecting element 8 and the respective components 2, 3 without complex measures, the radially inwardly directed, cylindrical surface 9 of the connecting element 8 is provided with a friction-enhancing coating 10, as described in Fig. 2 is schematically illustrated.

[0021] Here, a coating 10 is applied to the cylindrical surface 9 of the connecting element 8 - sketched in Fig. 2 - applied. The coating 10 consists of an electrolytically deposited metal layer 12 (in this case, a nickel layer) which is used to fix hard material particles 11 to the surface 9. The hard material 11 used here is diamond powder, which has diamonds with an average grain size of approximately 30 to 100 µm. The thickness t of the friction-enhancing coating 10 is accordingly small and is preferably in the range between 0.05 mm and 0.5 mm, particularly preferably in the range of less than 0.2 mm.

[0022] In Fig. Figure 3 shows a schematic representation of a device with which the cylindrical surface 9 of the connecting element 8 can be provided with the friction-enhancing coating 10. For this purpose, two cover elements 13 and 14 are attached to the end face of the connecting element 8, which, after their assembly, enclose a liquid-tight space 15; this space is partially bounded by the surface 9. The space 15 can also be referred to as the electroplating chamber.

[0023] Chamber 15 is then partially filled with an electrolyte. Furthermore, two anodes 16 are arranged in chamber 15, held by a corresponding bracket 17. A central shaft 18 passes through the bracket 17, driven by an electric motor 20 via a belt drive 19, which also rotates the connecting element 8. The shaft 18 is axially electrically insulated, i.e., electrical insulation 21 is arranged within the shaft 18. One part of the shaft 18 (in Fig. 3 (the left part) is electrically connected to the connecting element 8. The other part of the shaft 18 (in Fig. 3 (the right part) is electrically connected to the anodes 16 via the holder 17. A power source (not shown) is now connected such that the anodes 16 are connected to the positive terminal and the connecting element 8 to the negative terminal.

[0024] Accordingly, the anodes 16 function as sacrificial anodes, the material of which is deposited on the surface 9. The electrolyte contains hard particles, e.g., diamond particles, so that the deposition of the material from the anodes 16 forms a layer on the connecting element 8, which—as in Fig. Figure 2 illustrates the hard material particles being fixed. The slow and uniform rotation of the connecting element 8 during the electroplating process by the electric motor 20 creates a uniform layer on the surface 9. While, in this case, the nickel is deposited on the surface 9, the diamond particles floating in the electrolyte are thus fixed. The rotation repeatedly stirs the surface, resulting in a uniform, friction-enhancing coating 10.

[0025] The device for applying the friction-enhancing coating is advantageously very compact in design. Reference symbol list 1 Connection arrangement 2 first wave-shaped component 3 second wave-shaped component 4 Front face of the first wave-shaped component 5 Front face of the second wave-shaped component 6 axial end range 7 axial end area 8 Connecting element 9 radially inward-facing, cylindrical surfaces 10 friction-enhancing coating 11 hard particles 12 electrolytically deposited metal layer 13 Cover element 14 Cover element 15 liquid-tight room 16 Anode 17 bracket 18 wave 19 Belt drive 20 electric motor 21 electrical insulation t thickness D Outer diameter

Claims

[1] Connection arrangement (1) connecting a first shaft (2) to a second shaft (3), wherein the end face (4) of the first shaft (2) and the end face (5) of the second shaft (3) are opposite or abutting each other, wherein both shafts (2, 3) are radially enclosed in their axial end region (6, 7) by a sleeve-shaped connecting element (8), wherein the sleeve-shaped connecting element (8) is arranged on the two shafts (2, 3) by a shrink fit, wherein the sleeve-shaped connecting element (8) is at least partially provided on its radially inwardly directed, cylindrical surface (9) with a friction-enhancing coating (10), wherein the friction-enhancing coating (10) comprises hard particles (11) which are formed by an electrolytically deposited metal layer (12) on the inwardly directed,are fixed to the cylindrical surface (9) of the connecting element (8) and wherein the hard particles (11) are diamond particles, boron nitride particles, silicon carbide particles or corundum particles. [2] Connection arrangement (1) connecting a first shaft (2) to a second shaft (3), wherein the end face (4) of the first shaft (2) and the end face (5) of the second shaft (3) are opposite or abutting each other, wherein both shafts (2, 3) are radially enclosed in their axial end region (6, 7) by a sleeve-shaped connecting element (8), wherein the sleeve-shaped connecting element (8) is arranged on the two shafts (2, 3) by a shrink fit, wherein the sleeve-shaped connecting element (8) is at least partially provided on its radially inwardly directed cylindrical surface (9) with a friction-enhancing coating (10), wherein the friction-enhancing coating (10) is a zinc or molybdenum layer, wherein the zinc or molybdenum layer (10) is applied by an electroplating process or a spraying process. [3] Connection arrangement according to claim 1 or 2, characterized by, that the two shafts (2, 3) have the same outer diameter (D). [4] Connection arrangement according to claim 1, characterized by , that the electrolytically deposited metal layer (12) is a nickel layer. [5] Connection arrangement according to claim 2, characterized by that the friction-enhancing coating (10) is applied by a plasma spraying process or a flame spraying process. [6] Connection arrangement according to any one of claims 1 to 5, characterized by , that the thickness (t) of the friction-enhancing coating (10) is less than 0.5 mm, particularly preferably less than 0.2 mm. [7] Connection arrangement according to any one of claims 1 to 6, characterized by that the surface roughness (R a ) the friction-enhancing coating (10) has a value of at least 15 µm, preferably at least 20 µm. [8] Method for producing a sleeve-shaped connecting element (8) according to one of claims 1 or 2, which is provided on its radially inwardly directed cylindrical surface (9) with a friction-enhancing coating (10), comprising the steps: a) sealing the end faces of the connecting element (8) on both sides with cover elements (13, 14) so ​​that a liquid-tight space (15) is created; b) Inserting at least one anode (16) and filling the space (15) with an electrolyte containing hard particles (11), c) Applying a DC voltage between the connecting element (8) and the at least one anode (16) until a layer of desired thickness consisting of the material of the anode (16) has galvanically bonded to the radially inwardly directed cylindrical surface (9), whereby the space (15) is only partially filled with electrolyte and the connecting element (8) is rotated during step c).

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