Belt pulley for mounting on two types of pipe and for driving the pipe

Abstract

Pulley (10) for mounting on an end section (2) of a tube (1), which in a first variant has at least one end notch (3) and which in a second variant is free of end notches (3), wherein the pulley (10) has a drive section (11) via which the pulley (10) can be driven about an axis of rotation (A) and an axially adjacent cylindrical plug section (13) which is designed to be inserted into the end section (2) such that a cylindrical surface (31) of the plug section (13) can be arranged adjacent to an inner surface (4) of the end section (2), characterized in that the pulley (10) has at least one spring element (40) on its plug section (13) which is designed to correspond to a respective notch (3), wherein at least one spring element (40) in a fully extended primary position projects in radial direction (R) beyond the cylindrical surface (31) and is designed to support itself in circumferential direction (U) by forming an anti-rotation device at the respective notch (3), and wherein at least one spring element (40) is flush with the cylindrical surface (31) in a compressed secondary position.

Description

[0001] The invention relates to a pulley suitable for mounting on the end face of two different tube variants, allowing both tube variants to be driven about a rotational axis by the pulley. In the first variant, the tube has at least one end face cutout, while in the second variant, it is free of such end face cutouts.

[0002] Belt pulleys are known from the prior art. These can be used, for example, to drive a pipe or a shaft whose end section is designed as a pipe.

[0003] If the end section of the tube or shaft has notches (i.e., groove-shaped recesses, usually open in the axial direction), a pulley designed for this purpose has corresponding fixed projections which are inserted into the notches, so that they form an anti-rotation device that optimizes power transmission.

[0004] If the end section of the tube is free of notches in a different variant, or has a different number, distribution or shape of notches, the pulley with the protrusions cannot be used, so that essentially a separate pulley adapted to each variant of the tube must be provided, which leads to a corresponding variety of pulley variants with the associated high manufacturing and storage costs.

[0005] Various devices for connecting to a pipe and aspects of such devices are known, for example, from documents DE 10 2020 125 328 A1, DE 10 2020 000 366 A1, DE 60 2005 006 015 T2, EP 0 359 653 A1 and US 2008 / 0 139 351 A1.

[0006] The invention is therefore based on the objective of overcoming the aforementioned disadvantages and providing a pulley that is suitable for driving and mounting various types of pipe, the types of pipe differing in particular in the presence of or number of notches on their end section.

[0007] This problem is solved by the combination of features according to claim 1.

[0008] According to the invention, a pulley for mounting, in particular by push-fit mounting and further specifically by insertion, on an end section of a pipe is proposed. In a first embodiment, the pulley has at least one end-face cutout in or on its end section, and in a second embodiment, its end section is free of end-face cutouts. As already explained, a cutout is understood to be a recess, preferably open in the axial direction, which completely extends through the pipe wall in the thickness direction. For the sake of clarity, the intention is to provide a pulley that can be mounted both on a pipe with end-face cutouts and, alternatively, on a pipe without end-face cutouts, so that both versions of the pipe can be driven by the pulley.For this purpose, the pulley has a drive section via which the pulley, and thus the tube, can be driven about an axis of rotation. The drive section preferably has grooves or slots extending circumferentially or axially for driving by means of a belt, which can be, for example, a toothed belt, a V-belt, or another belt suitable for power or motion transmission. Particularly preferably, the drive section has grooves or slots that correspond to a belt known at the time of application as a poly-V belt. The pulley can therefore preferably be driven via its drive section by means of such a poly-V belt. In the axial direction, i.e.,Along the axis of rotation adjacent to the drive section, the pulley further features a cylindrical plug-in section, preferably concentric to the axis of rotation, which is designed for insertion and preferably press-fitting into the end section. This allows a cylindrical surface of the plug-in section to be positioned adjacent to an inner surface of the end section and brought into contact with it by insertion or press-fitting. Depending on whether an interference fit is required, the outer diameter of the cylindrical plug-in section can correspond to the inner diameter of the end section. It should also be noted that an interference fit is not mandatory, nor is assembly by press-fitting required. Alternatively, the pulley can, for example, be inserted into the end section, and the end section can then be deformed to reduce its diameter.According to the invention, the pulley has at least one spring element at its connecting section, which is configured to correspond to a respective notch or notches. Accordingly, the width of the spring element in the circumferential direction can correspond to the width of the notch in the circumferential direction or be smaller than it within a predetermined tolerance. In a primary extended position, which can be designated as or serves as the home position, the at least one spring element projects radially beyond the outer surface and is configured to engage a notch in the circumferential direction, and in particular on both sides in the circumferential direction, thus forming an anti-rotation device that fixes the position of the pulley in the tube in the circumferential direction and optimizes force transmission between the pulley and the tube.Furthermore, the at least one spring element in a compressed secondary position preferably closes flush with the outer surface, i.e., does not protrude beyond the outer surface in the radial direction, so that the at least one spring element can be compressed or brought into the secondary position when the pulley is inserted into the end section of a variant free of cutouts, and the insertion into a variant of the tube free of cutouts is not hindered.

[0009] As a general rule, preferably one spring element is provided for each notch. However, this is not mandatory. For example, a fixed, predetermined number of spring elements can be provided so that when the pulley is inserted into an end section with fewer notches, spring elements not engaging in the notches are compressed into their secondary position.

[0010] Furthermore, all cutouts and all spring elements can be designed in the same way.

[0011] According to an advantageous embodiment, it is also provided that the pulley forms a collar section in the axial direction between the drive section and the plug-in section, which projects radially beyond the cylindrical surface of the plug-in section and forms an axial stop in the direction of the plug-in section for axial contact with the end section and for axial positioning of the plug-in section in the end section.

[0012] Preferably, the maximum outer diameter of the collar section is larger than the maximum inner diameter of the tube at its end section and at the same time equal to or smaller than the maximum outer diameter of the tube at its end face.

[0013] Furthermore, it is preferably provided that a lateral surface of the collar section is designed to transition seamlessly into an outer surface of the pipe or the end section.

[0014] With regard to a forming of the tube after insertion of the pulley, for example by rolling or flanging, which reduces the diameter at the end face, it can also be provided that a maximum outer diameter of the collar section is equal to the outer diameter at the end face of the tube reduced by forming, so that a flush and seamless transition can be produced.

[0015] Preferably, the pulley in the plug-in section forms a pocket, in particular for each spring element, which sectionally surrounds the respective spring element and forms a receiving space, open exclusively radially outwards, for receiving the respective spring element in the secondary position, so that the respective spring element can spring into the pocket, but there is no radial inwards connection to a receiving space of a hollow cylindrical pulley, which will be explained in more detail below, so that no foreign bodies or liquids can penetrate into the receiving space.

[0016] Preferably, the at least one pocket and the receiving space formed thereby are directly adjacent to the collar section, and the spring element can also extend to the collar section.

[0017] Alternatively, it can also be provided that the at least one pocket with the associated spring element is spaced axially from the collar section. If the at least one cutout is not designed as an open-ended recess, but, for example, as an axially closed hole or slot, the at least one spring element can serve not only as an anti-rotation device, but also as a locking element designed to engage in such a hole or slot. By engaging in the hole or slot, the pulley can be additionally secured axially within the tube or end section against unwanted axial displacement.

[0018] Preferably, the at least one spring element is designed to be flush with a lateral surface of the collar section in its primary position, so that the at least one spring element does not protrude beyond it in the radial direction. Alternatively, it can also be provided that the at least one spring element, in its primary position, lies completely behind the lateral surface of the collar section in the radial direction, so that in this variant, too, the spring element does not protrude beyond the collar section in the radial direction.

[0019] Particularly with regard to a forming process that reduces the outer diameter of the end section or the end face of the tube, an advantageous embodiment of the invention provides that the lateral surface of the plug-in section preferably has a radial recess or a radial recess immediately adjacent to the collar section, which preferably completely surrounds the axis of rotation in the circumferential direction and is designed to accommodate a radially inwardly deformed or formed end face of the end section after the belt pulley has been inserted into the end section, for example by flanging, thereby enabling a force-fit and / or form-fit connection between the tube and the belt pulley.

[0020] Furthermore, the connector section is equipped with a multitude of spring elements, or at least two spring elements, which are uniformly or regularly distributed around the axis of rotation, i.e., with equal circumferential spacing. A regular distribution does not necessarily have to correspond to a uniform distribution. For example, the distance between the spring elements can be chosen to vary in such a way as to create a predetermined asymmetry and coding.

[0021] Furthermore, it is preferably provided that each pair of spring elements of the plurality of spring elements is arranged offset from each other around the axis of rotation by, in particular, 180°, thereby further optimizing the force transmission.

[0022] Although a multi-part construction of the hollow cylindrical pulley may be provided, in which, for example, the at least one spring element is formed by a spring-elastic spring body and an element sprung by it, it is preferably provided that the pulley is formed in one piece and, further preferably, in one piece.

[0023] In this case, at least one spring element can be provided, for example, as a spring arm. This has a free end in the axial direction to the drive section and a connection section in the opposite axial direction, at which the respective spring element is connected, in particular by a material bond, to a wall of the plug-in section that defines the outer surface.

[0024] To enable the pulley to be inserted into the end section of the tube with minimal additional resistance, at least one spring element can transition seamlessly into the wall of the insertion section at its connection point. Additionally or alternatively, at least one spring element can form a predetermined guide surface extending radially outwards from its connection point to its free end. This guide surface allows the spring element to be moved from the primary position to the secondary position with a predetermined force and / or along a predetermined spring path when the pulley is inserted into the end section of the tube.

[0025] As previously explained, the pulley can be hollow cylindrical, and it can further be designed to be open at least on one side in the axial direction. Inside, the pulley forms a receiving space, preferably extending over substantially its entire axial length, for a radial bearing. This bearing allows the pulley, with the tube mounted or fixed to it, to be supported on an axis and driven around that axis. The receiving space is completely closed radially outwards by the pulley, preventing the ingress of foreign objects or liquids in the radial direction.

[0026] The at least one open end of the pulley can also be closed by a seal and in particular by a sealing cap with a sealing element formed on it, such as a labyrinth seal, and in particular closed off from the axle, so that the ingress of foreign bodies, i.e. in particular dirt, is prevented or at least made more difficult.

[0027] The features disclosed above can be combined in any way, provided that this is technically possible and they do not contradict each other.

[0028] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. The figures show: Fig. 1 a perspective view of an end section of a tube having notches on its end face with a pulley inserted therein; Fig. 2 a sectional view through an end section of a tube having notches on its end face with a pulley inserted therein; Fig. 3 a sectional view through an end section of a tube free of cutouts on its end face with a pulley inserted therein.

[0029] The figures are schematic examples. Identical reference symbols in the figures indicate identical functional and / or structural features. In the Fig. The unit consisting of pipe 1 and pulley 10 shown in Figure 1 can in particular be the unit consisting of pipe 1 and pulley 10 according to Fig. 2. The pulley 10 according to the Fig. 1 to 3 are preferably identical or at least identically designed.

[0030] A key aspect of the invention is to provide a pulley 10 which can be inserted into both an end section 2 of a tube 1 with end-face notches 3 and an end section 2 of a tube 1 without end-face notches 3, so that the respective tube 1 can be driven by the pulley 10 in circumferential direction U about a rotational axis A.

[0031] This is what is in the Fig. The pulley 10 shown in Figures 1 to 3 is essentially divided into three sections in the axial direction, i.e., along the axis of rotation. Between a drive section 11 on a side of the pulley 10 facing away from the tube 1 and a section in the Fig. 1 to 3 arranged within pipe 1 and in Fig. In the non-visible plug section 13, a collar section 12 is provided, on which an axial stop 22 is formed towards the plug section 13, which forms an axial stop for the end face of the tube 1 and thereby determines the axial position of the pulley 10 or its plug section 13 in the tube 1.

[0032] The pulley 10 has several spring elements 40 in its plug-in section 13, and in this example two opposing spring elements 40, offset from each other by 180° with respect to the axis of rotation A, of which the chosen representation and the respective section view in the Fig. 1 to 3 only one spring element 40 is visible.

[0033] If a pulley 10 designed according to the invention is inserted into an end section 2 of a tube 1 or a shaft designed as a tube 1 in the end section 2, and this shaft has cutouts 3 on its end side, as shown in Fig. As shown in Figure 2, the spring elements 40 are guided directly, or optionally by means of an additional rotation of the pulley 10 in the circumferential direction U relative to the tube 1, into the notches 3, so that the spring elements 40 are in their position in the Fig. 1 and Fig. 2 shown, the spring elements 40 support the primary or basic position in the circumferential direction U at the respective notch 3 and more precisely at a wall of the tube 1 that limits the notches 3 and form a rotation lock, whereby, when the tube 1 is driven about the axis of rotation A via the pulley 10, a torque or force can be advantageously transmitted to the tube 1 via the spring elements 40.

[0034] If the belt pulley 10 designed according to the invention is to be inserted into a tube 1 without end-face notches 3, as is the case in Fig. As shown in Figure 3, when the plug section 13 is inserted into the tube 1, the spring elements 40 are moved by the tube 1 from their primary position into a compressed secondary position, in which the spring elements 40 are completely immersed in a receiving space 32 formed around them.

[0035] Regardless of the variant of pipe 1 according to Fig. 2 or a variant of pipe 1 according to Fig. 3 the pulley 10 can be pressed into the respective tube 1, so that a lateral surface 31 of the plug section 13 is pressed directly against an inner surface 4 of the tube 1 and a corresponding connection is made.

[0036] In order to permanently fix the respective tube 1 to the pulley 10 or vice versa, the outer surface 31 is provided to form a circumferential recess 33 immediately adjacent to the collar section 12, extending completely around the axis of rotation A in the circumferential direction U. The tube 1 or its end face can be deformed and, for example, flanged into this recess, so that the tube 1 and pulley 10 are permanently connected, as is also shown in the Fig. Figures 1 to 3 are shown. For clarification, the pulley 10 is first inserted into a tube 1 or its end section 2, the end of which has not yet been deformed to reduce its inner diameter.

[0037] With regard to the spring element 40, it is advantageous that its free end 43 in the primary position of the spring element 40 is flush with a lateral surface 21 of the collar section 12 in the radial direction R, i.e., does not protrude beyond the lateral surface 21 of the collar section 12 in the radial direction R, so that the spring element 40 does not form an obstacle hindering rotation even in its primary position.

[0038] At its connection section 11 opposite the free end 43, the spring element 40 transitions materially into a wall 34 of the plug section 13 and seamlessly into the lateral surface 31 of the plug section 13 defined by the wall 34.

[0039] In order to prevent the spring elements 40 from being accidentally moved from the primary position to the secondary position only when and with a predetermined force, a guide surface 42 is provided radially outside the connection section 41 and extending towards the free end 43, through which the force required for this is specified.

[0040] The pulley 10 is, as particularly in the Fig. 2 and Fig. As can be seen, the housing 15 is hollow and cylindrical, allowing a radial bearing 5 to be arranged in a receiving space 15 that is open on both sides in the axial direction. The belt pulley 10 can be mounted on a shaft (not shown) so that it can rotate about the axis of rotation A by means of the radial bearing 5.

[0041] On the side of the pulley 10 facing away from the tube 1, or on the end face of the pulley 10 formed by the drive section 11, the receiving chamber 15 is closed by a cover or sealing cap 6, which together with the end face of the pulley 10 forms a labyrinth seal 7 radially outward. A sleeve-like extension 8 extends radially inward into the receiving chamber 15 and preferably into the radial bearing 5, so that the radial bearing 5 is not directly supported on the shaft, but rather via the sleeve-like extension 8.

[0042] The invention is not limited in its implementation to the preferred embodiments specified above. Rather, a number of variants are conceivable which make use of the solution presented even in fundamentally different designs.

Claims

[1] Pulley (10) for mounting on an end section (2) of a tube (1), which in a first variant has at least one end notch (3) and which in a second variant is free of end notches (3), wherein the pulley (10) has a drive section (11) via which the pulley (10) can be driven about an axis of rotation (A) and an axially adjacent cylindrical plug section (13) which is designed to be inserted into the end section (2) such that a cylindrical surface (31) of the plug section (13) can be arranged adjacent to an inner surface (4) of the end section (2), characterized by , that the pulley (10) has at least one spring element (40) on its plug section (13) which is designed to correspond to a respective notch (3), wherein at least one spring element (40) projects in a fully extended primary position in radial direction (R) beyond the cylindrical surface (31) and is designed to support itself in circumferential direction (U) by forming an anti-rotation device at the respective notch (3), and wherein at least one spring element (40) is flush with the cylindrical surface (31) in a compressed secondary position. [2] Pulley according to claim 1, wherein a collar section (12) is formed in the axial direction between the drive section (11) and the plug section (13), which projects in the radial direction (R) beyond the cylindrical surface (31) of the plug section (13) and forms an axial stop (22) in the direction of the plug section (13) for axial contact with the end section (2) and axial positioning of the plug section (13) in the end section (2). [3] Pulley according to claim 1 or 2, wherein in the plug section (13) in particular a pocket (32) is formed for each spring element (40) which partially surrounds the respective spring element (40) and which forms a receiving space which is open in particular exclusively to the radial outside for receiving the respective spring element (40) in the secondary position. [4] Pulley according to claims 2 and 3, wherein the at least one pocket (32) and the receiving space formed therein are directly adjacent to the collar section (12). [5] Pulley according to any one of claims 2 to 4, wherein at least one spring element (40) in its primary position is flush with a lateral surface (21) of the collar section (12) in the radial direction (R). or wherein at least one spring element (40) in its primary position in radial direction (R) lies completely behind the lateral surface (21) of the collar section (12). [6] Pulley according to one of claims 2 to 5, wherein the cylindrical surface (31) of the plug-in section (13) has a radial recess (33) in particular immediately adjacent to the collar section (12), which is designed to accommodate a radially inward deformed end face of the end section (2) after the pulley (10) has been inserted into the end section (2). [7] Pulley according to any one of the preceding claims, wherein a plurality of spring elements (40) are provided on the plug section (13), which are evenly or regularly distributed in the circumferential direction (U) around the axis of rotation (A), wherein two spring elements (40) of the plurality of spring elements (40) are arranged offset from each other about the axis of rotation (A) by, in particular, 180°. [8] Pulley according to one of the preceding claims, wherein the at least one spring element (40) has a free end (43) in the axial direction to the drive section (11) and a connection section (41) in the opposite axial direction, to which the respective spring element (40) is connected, in particular by a material bond, to a wall (34) of the plug section (13) which determines the outer surface (31) of the plug section (13). [9] Pulley according to the preceding claim, wherein the at least one spring element (40) transitions seamlessly into the wall (34) of the plug-in section (13) at its connection section (41) and / or wherein the at least one spring element (40) forms a guide surface (42) radially outward from its connection section (41) to its free end (43), through which the spring element (40) can be moved from the primary position to the secondary position with a predetermined force. [10] Pulley according to any one of the preceding claims, wherein the pulley (10) is hollow cylindrical and open at least on one side in the axial direction and forms a receiving space (15) inside for receiving a radial bearing (5), wherein the receiving space (15) is completely closed radially outwards.

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