Belt tension roller set and method for producing a belt tension roller

Abstract

According to a universal concept, different belt tensioning rollers (1) are produced, where the bodies (2) of the different belt tensioning rollers (1) are additively manufactured based on the same basic roller shape (GF) by subjecting the basic roller shape (GF) to different deformations, each of the bodies (2) having at least one reinforcement (9, 14, 15), each of the bodies (2) being able to be combined with a rolling bearing (10).

Description

[Technical Field]

[0001] The present invention relates to a method for producing a belt tensioning roller, the method including generative production of at least a portion of the belt tensioning roller. The present invention further relates to a set of at least partially generatively manufactured belt tensioning rollers for a traction drive. [Background technology]

[0002] German Patent Application No. 102019132263 describes a method for the additive production of belt tensioning rollers for traction drives. The ring element of the belt tensioning roller has an outer peripheral surface for contacting the belt, i.e., the traction means, and an inner peripheral surface for receiving a bearing. At least a portion of the ring element is additively, i.e., manufactured, and contains nanoparticles. The nanoparticles may be unevenly distributed in the additively manufactured portion of the ring element and may contain ceramic portions. German Patent Application No. 102019132263 proposes a powder-based additive manufacturing method as a manufacturing technique.

[0003] DE 3831769 A1 describes a roller for a belt drive, which includes a carrier made of an electrically non-conductive polymer material and an annular metal body, the contact surface for the belt running on the roller being provided by an electrically conductive material, which is in electrical communication with the annular metal body.

[0004] DE 102006039363 A1 discloses a belt tensioning roller with a PVD coating, which is arranged on the running surface of the belt tensioning roller for contacting the belt, and other components of the belt tensioning roller, such as its bearing system, may also be PVD coated.

[0005] DE 102011003020 A1 discloses a plastic tension and / or deflection roller with a nanocrystalline coating, which is at least partially disposed on the outer circumferential surface of the plastic body of the tension and / or deflection roller intended for use in traction drives.

[0006] DE 102009038220 A1 relates to a belt tensioning roller with an integrated oil trap unit. DE 102009038220 A1 describes plastic injection molding and non-cutting sheet metal forming as manufacturing techniques that can be used to produce the components of the belt tensioning roller. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention is based on the object of developing the production of belt tension rollers in relation to the above-mentioned prior art in order to achieve an extremely high degree of flexibility in production. [Means for solving the problem]

[0008] This object is achieved by a method for producing a belt tensioning roller according to claim 1. This object is further achieved by a set formed by a belt tensioning roller according to claim 5. Features and advantages of the invention described below in relation to the device, i.e. the belt tensioning roller set, also apply mutatis mutandis to the production method, i.e. the generative manufacturing method, and vice versa.

[0009] The production method is based on the same basic roller shape of the belt tensioning roller, on which basis different bodies of the belt tensioning roller, each having at least one reinforcement, can be produced in various variants.

[0010] The belt tensioning roller set comprises a plurality of different bodies, each of which is additively produced by the method according to claim 1 and is adapted to receive a rolling bearing, in particular a ball bearing, held in the inner wall of the body, each of which has two cavities with a toroidal basic shape, an outer cavity bounded by the belt support wall and an inner cavity bounded by the inner wall.

[0011] Since various variations of the basic roller shape can be implemented with little effort, a large number of different belt tensioning rollers can be provided, each designed to meet specific requirements. Small series, in particular, can be efficiently produced based on the same basic concept. A significant advantage is that oversized rollers, which are associated with unnecessarily large masses and moments of inertia, are not necessary. Conversely, in the case of small-scale production runs with particularly high material requirements, such as those for motorsport, the adaptation of reinforcements allows for ample reserves in terms of capacity, while still rationally avoiding oversizing of components.

[0012] The reinforcement of the body of the belt tensioning roller may in particular be in the form of a reinforcing web. Additionally or alternatively, the reinforcement may be implemented in the form of an increased wall thickness. In both cases, the body may be constructed synthetically from powder material, and a depowdering opening in the body, which opens in the direction of the body's central axis, may be excluded. The depowdering opening may in particular be configured elliptical and funnel-shaped, ensuring that powder remains in the corners of the cavity as little as possible and that expansion options are minimally affected by the reinforcing web.

[0013] In principle, the body can also be constructed using filaments instead of powder material, and the filament material may be constructed homogeneously or heterogeneously, in particular with reinforcing fibers.

[0014] The individual rollers of the belt tensioning roller set may have reinforcing webs, especially in the outer cavities of their bodies. There are a great number of possible variations in the shape and arrangement of these reinforcing webs. In particular, different reinforcing webs may be staggered around the circumference of the outer cavities.

[0015] To absorb significantly larger radial forces, further reinforcements extending to the inner walls of the two cavities may in each case be arranged in the extension of the reinforcement of the outer cavity, this further reinforcement web making it particularly easy to absorb uneven loads, e.g. loads that are significantly larger near one end face of the belt tensioning roller than near the other end face.

[0016] According to various possible developments, the body of the belt tensioning roller can have a rim on one or both sides of the belt support wall. In the case of generative manufacturing, i.e., 3D printing, the attachment of the rim is independent of the above-mentioned method of reinforcing the body of the belt tensioning roller. The rim on one side can be attached in a manner suitable for production so that no overhangs occur and can provide an additional support structure for support during generative, additive production without having to compromise on dimensional accuracy. This also contributes to shortening the production time by minimizing the volume of the 3D printed part and at the same time eliminating or at least limiting the need for finishing operations.

[0017] In the following, some exemplary embodiments of the invention are explained in more detail with the aid of the drawings. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of a first exemplary embodiment of a body of a belt tensioning roller for a belt drive. FIG. [Figure 2] 2 shows the arrangement of reinforcing webs in the body of the belt tensioning roller according to FIG. 1; [Figure 3] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 4] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 5] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 6] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 7] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 8] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 9] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 10] 1 and 2, showing a further embodiment of the body of the belt tensioning roller. [Figure 11] 1 to 10 show the body of the belt tensioning roller with additional outer reinforcing webs. [Figure 12] 12 shows a belt tensioning roller constructed with a rolling bearing and a body according to FIG. 11; [Figure 13] 13 shows the body of a belt tensioning roller with increased wall thickness compared to the embodiment according to FIGS. 1 to 12. [Figure 14] 1 shows the basic unreinforced shape of the belt tension roller body. [Figure 15] 1 shows the body of a belt tensioning roller with one rim. [Figure 16] Shows the body of a belt tension roller with two rims. [Figure 17] FIG. 10 is a perspective cross-sectional view of the body of a further belt tensioning roller. [Figure 18] FIG. 18 is a cross-sectional view of the main body according to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Unless otherwise stated, the following description relates to all exemplary embodiments. In all figures, parts that correspond to each other or have essentially the same effect are provided with the same reference numerals.

[0020] The belt tensioning roller 1 includes a body 2, which is produced synthetically from a powder starting material, whether plastic or metal, and a rolling bearing 10, i.e., a ball bearing, held in the body 2. The rolling bearing 10 has an outer ring 11, a number of balls as rolling elements 12, and an inner ring 13. A cage guiding the balls 12 and a seal enclosing the rolling bearing 10 are not shown. The outer ring 11 of the rolling bearing 10 is in contact with an inner wall 6, which belongs to the wall of the body 2, generally designated 4. The inner wall 6 defines an inner cavity 5 of the body 2. In addition, the body 2 defines an outer cavity 7, which is bounded, inter alia, by a belt support wall 8, on which the belt rests during operation of the belt tensioning roller 1. As shown in the figure, the belt support wall 8 has a spherical shape.

[0021] During the generative production of the body 2, the body 2 is built from powder material in a build direction AR starting from the support surface 3. All modifications of the body 2 are based on a basic shape GF, which is shown in Figure 14. The central axis of the body 2 is indicated by MA.

[0022] During operation of the belt tensioning roller 1, a support force AF is generated, which loads the belt support wall 8. Depending on the magnitude of the estimated support force AF, the body 2 has a suitable reinforcement 9. The reinforcement 9 is in the form of reinforcing webs 14, 15 (Figures 1 to 12) or in the form of a wall reinforcement (Figures 13 and 14 to 18). A reinforced wall 4 may also be combined with additional reinforcing webs 14, 15. A set of belt tensioning rollers 1 includes bodies 2 reinforced in various ways, and part of this set may be belt tensioning rollers 1 having bodies 2 in the basic shape GF without reinforcement.

[0023] In the embodiment according to Figures 1 to 10, the reinforcing web 15 may be present only in the outer cavity 7. In this case, the term inner reinforcing web 15 is used, since the reinforcing web 15 is located in the cavity 7. In any of the exemplary embodiments, no reinforcing web is present in the inner cavity 5.

[0024] Figures 2, 4, 6, 8 and 10 show the reinforcing webs 15 of the body 2 according to the corresponding Figures 1, 3, 5, 7 and 9 (which may be on the left side of the drawing page) after the arrangement is complete. In all cases, the width of each reinforcing web 14, 15 measured in the circumferential direction is indicated by BS. AS denotes the distance between two adjacent reinforcing webs 14, 15 measured in the same direction.

[0025] 1 and 2, the reinforcing webs 15 are located at various positions within the outer cavity 7, and not only are their axial positions staggered around the circumference of the outer cavity 7, and therefore of the entire body 2, but their inclinations also staggered. In the case of FIGS. 1 and 2, the imaginary center plane of the belt tensioning roller 1, located between both end faces of the body 2, intersects all of the reinforcing webs 15, and the individual reinforcing webs 15 are staggered between the side closer to one end face of the body 2 and the side closer to the other end face.

[0026] In the exemplary embodiment according to Figures 3 and 4, all reinforcing webs 15 have the same shape, symmetrical to the central plane of the body 2, and the reinforcing webs 15 appear V-shaped in cross section. The additional material introduced into the body 2 in the form of reinforcing webs 15 is greater in the case of Figures 3 and 4 than in the case of Figures 1 and 2, compared to the basic shape GF.

[0027] In the cases of Figures 5 and 6, the increase in material is even less than in the cases of Figures 1 and 2. In this case, the reinforcing webs 15 are located near both end faces of the body 2, and the central plane extending through the body 2 does not intersect any of the reinforcing webs 15.

[0028] In the case of Figures 7 and 8, the reinforcing webs 15 are arranged asymmetrically and each individual reinforcing web 15 is V-shaped. The variant according to Figures 7 and 8 therefore represents a fusion of the variants according to Figures 1 and 2 and Figures 5 and 6 on the one hand with the variant according to Figures 3 and 4 on the other hand. In the case of Figures 7 and 8, each V-shaped reinforcing web 15 has two V-legs of different lengths.

[0029] The asymmetric V-shape can also be seen in the variant reinforcing web 15 according to FIGS. 9 and 10, where two V-shapes merge to form a W-shaped reinforcing web 15.

[0030] The variant according to Figures 11 and 12 shows a modification of the configuration according to Figures 9 and 10, in which in addition to the inner reinforcing webs 15, outer reinforcing webs 14 located outside the cavities 5, 7 can be seen. From Figures 11 and 12 it can be seen that each outer reinforcing web 14 represents an extension of the inner reinforcing web 15.

[0031] In each of the configurations according to Figure 13 and Figures 15 to 18, the reinforcement 9 is exclusively in the form of a wall reinforcement. The configuration according to Figure 15 differs from the configuration according to Figure 13 in that a rim 17 is formed on one side. In the case of Figure 16, there is also a second rim 18 with a cross-sectional shape different from that of the rim 17.

[0032] The external shape of the variants according to Figures 17 and 18 corresponds to the shape of the body 2 according to Figure 13. In addition, openings 16 can be seen in the body 2 in Figures 17 and 18, which allow depowdering as part of generative production. For the same purpose, openings may also be present in the body 2 of the other variants already described. Parts of the wall 4, in particular the wall part of the outer cavity 7 facing the inner wall 6, may also be designed as a lattice rather than as a closed surface. The same applies to the wall part of the inner cavity 5 facing away from the inner wall 6. [Explanation of symbols]

[0033] 1 Belt tension roller 2 Main unit 3 Support surface 4. Wall 5 inner cavity 6 Inner wall 7 outer cavity 8 Belt support wall 9 Reinforcement 10 Rolling bearings 11 outer ring 12 Rolling elements 13 Inner ring 14 Outer reinforcement web 15 Inner reinforcing web 16 Main body opening 17 Rims 18 rims AF Support Capacity AR Construction Direction AS the distance between two webs BS Web Width GF basic shape MA center axis

Claims

1. A method for producing a belt tension roller (1), wherein different bodies (2) of the belt tension roller (1) having at least one reinforcing portion (9, 14, 15) based on the same basic roller shape (GF) are generatively produced by setting the arrangement of the reinforcing portion (9, 14, 15) relative to the basic roller shape (GF) and by setting the shape of the reinforcing portion (9, 14, 15).

2. 2. A method according to claim 1, characterized in that at least one reinforcement (9) has an increased wall thickness with respect to the basic roller shape (GF).

3. 2. The method according to claim 1, characterized in that the body (2) is constructed from a powder material and that an opening (16) in the body (2) for depowdering is formed in the direction of the central axis (MA) of the body (2).

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