Conveyor roller with friction and / or material-locking coupling bushing

Description

[0001] The invention relates to a motor-driven conveyor roller for conveyor systems for conveying containers, pallets and the like, comprising a roller body whose outer peripheral surface represents a support surface for conveyed material, a drive unit arranged within an interior space of the roller body, and a coupling unit designed to transmit a torque from the drive unit to an inner peripheral surface of the interior space of the roller body, which coupling unit has a coupling bushing having a drive section connected to the drive unit and an outer peripheral output section.

[0002] Motor-driven conveyor rollers of this type are used for a variety of purposes in logistics applications. For example, they can be used for pallet conveying, for conveying parcels in parcel shipping centers, for conveying containers in various types of warehouses, for baggage transport in airports, and in numerous other applications. Such motor-driven conveyor rollers are regularly used in conveyor lines consisting of several rollers arranged side by side, each of whose upper circumferential surface serves to hold the material being conveyed. These conveyor lines contain idler rollers, which are driveless and are simply mounted for rotation in a conveyor frame. These conveyor lines also contain driven conveyor rollers, which are motor-driven and rotated by an electric drive unit.These motor-driven conveyor rollers are designed in such a way that the drive unit is located within the roller itself, so that no mechanical components located outside the roller body are required to generate the roller's rotation. On the one hand, the motor-driven conveyor rollers serve to transport the conveyed material directly via the outer circumferential surface of their roller body. On the other hand, by transferring the rotation of the motor-driven conveyor roller to one or more idler rollers via a transmission element, such as a belt drive, the motor-driven conveyor roller can also rotate the idler rollers, thus driving the conveyed material via their outer circumferential surface.

[0003] EP 1 656 312 B1 discloses a motor-driven conveyor roller in which the drive unit is arranged inside the conveyor roller. This motor-driven conveyor roller has a pressure unit comprising a first and a second disc that define a V-shape on the outer circumference, into which an elastic pressure ring is inserted. The two discs can be pushed onto a conical drive shaft of the drive unit and pressed together by means of a central screw.This creates a frictional, torque-resistant connection to the drive shaft between one of the two discs. At the same time, the pressure ring is compressed from a state in which it can be inserted into the inner circumference of the roller body to a tensioned state in which the pressure ring is deformed radially outward, forming a press fit with both the two conical clamping surfaces of the discs, which form the V-shape, and the inner circumferential surface of the roller body. This frictional coupling transfers the drive torque of the drive unit to the roller body.

[0004] It has been shown that noise development can be high with this type. Therefore, an improved conveyor roller was proposed in DE 20 2012 005 380 U1, in which a coupling unit is provided for transmitting torque from the drive unit to an inner circumferential surface of the interior of the roller body. The coupling unit comprises a clamping bushing, a clamping ring that is axially movable relative to the clamping bushing, a fastening element for holding an axial position of the clamping ring relative to the clamping bushing in a clamped position, and a pressure ring that is fixed between a clamping surface of the clamping bushing and a clamping surface of the clamping ring in the clamped position and, in the clamped position, is in frictional engagement with the inner circumferential surface of the interior of the roller body around its outer circumference. The clamping bushing of the coupling element has an inner cavity, and the fastening element is arranged radially outward from this cavity.

[0005] While both solutions have proven well-suited for transmitting torque, one problem is that, especially with fluctuating tolerances, the preload can be too high, resulting in a bulge on the outer surface of the roller body. This is highly undesirable in roller operation.

[0006] Another problem with lubricated motor-driven conveyor rollers is that the frictional engagement can be impaired by an oil film. While it is possible to clean the roller body from the inside during or before installation, this cannot ensure permanent oil-free operation.

[0007] Furthermore, according to DE 10 2015 120 922 A1, a solution was proposed in which an energy transmission element is used, which comprises a connecting element, an intermediate element, and an engaging element. The connecting element has an annular portion. The outer peripheral surface of the annular portion is provided with arcuate portions, and the inner peripheral surface of the annular portion is provided with concave-convex portions. The engaging element has projections and a shaft insertion hole. The arcuate portions of the connecting element are in contact with the inner peripheral surface of the roller body, and the connecting element and the roller body are also securely connected to each other by means of a securing device.The intermediate element engages with the concave-convex regions and the projections, the shaft insertion hole of the engaging element is held in the center of the roller body, and a drive unit engages with the shaft insertion hole. Individual projections or pins are provided for transmitting torque. These extend radially from the peripheral inner surface of the roller body and can engage the recesses of the connecting element. During the examination procedure, the granting authority assumed that DE 10 2015 120 922 A1 discloses the features of the preamble of claims 1 and 13.

[0008] Although the positive engagement between the drive and the roller body prevents the problem of deformation of the roller body due to excessive pressure, the design is very complex. Furthermore, tight tolerances must be maintained during manufacturing, which incurs costs. Maintenance also poses a problem if the positive connection is defective. A clamping connection, which is also known from the prior art, can be easily readjusted, whereas a positive connection requires replacement of the parts.

[0009] The following prior art is also known from the European examination procedure: DE 10 2015 120922 A1, JP 2015 214379 A and DE 203 19 969 U1.

[0010] The object of the present invention is therefore to provide a conveyor roller of the type mentioned at the outset which is simplified in terms of construction and in which a reliable torque transmission from the drive to the conveyor roller is possible even with wide tolerances without deformation of the roller body.

[0011] The object is achieved by a motor-driven conveyor roller according to claim 1. Furthermore, the object is achieved by a motor-driven conveyor roller according to claim 13.

[0012] In contrast to the prior art, which provided for a circumferential frictional connection on the one hand or a positive connection on the other, the present invention proposes the use of a point-based frictional connection or a point-based material-to-material connection. Both frictional and material-to-material connections are significantly simpler in design than positive connections. They allow for significantly higher tolerances than positive connections, thereby reducing manufacturing costs. A point-based frictional connection is also simpler than a circumferential frictional connection, as it also allows for higher tolerances. This avoids the problem of excessive pressure due to insufficient tolerances, thus simplifying production overall and making the conveyor roller more cost-effective to manufacture.

[0013] A point-based frictional connection, as proposed by the invention, also has the advantage that oil present on the inner circumferential surface of the roller body can be more easily displaced. Thus, the invention makes it possible to achieve an effective frictional connection even with oil-lubricated conveyor rollers, without the need for laborious degreasing or the frictional connection deteriorating during operation.

[0014] The invention is based on the finding that motor-driven conveyor rollers do not require very high torques to be transmitted, and therefore a point-based frictional connection is sufficient, in contrast to a circumferential frictional connection, which provides a significantly larger surface area for torque transmission. This allows the advantage of the point-based frictional connection to be utilized, in particular the compensation of manufacturing tolerances, thereby simplifying production. A material-to-material connection offers a similar advantage, as it can also compensate for manufacturing tolerances when applied at points. Therefore, both variants are equally preferred and solve the same problem.

[0015] According to a first preferred embodiment, the output section of the coupling bushing has a plurality of radial lugs designed to be in contact with the inner circumferential surface of the roller body. The lugs thus form contact points at which a punctiform frictional connection is established between the coupling bushing and the roller body. The lugs are preferably rounded in cross-section and / or have a slightly trapezoidal shape, which forms a slight plateau at the radially outer end. The lugs preferably have an outer contour that is approximately partially cylindrical and extends at least partially, preferably completely, over the coupling bushing in the axial direction.

[0016] Preferably, the radial projections together define a diameter that is larger than the diameter of the inner circumferential surface. This achieves a particularly good frictional connection between the coupling bushing and the roller body, as the projections together define an oversize, ensuring that the coupling bushing is inserted into the roller body under preload.

[0017] For this purpose, the lugs are preferably designed to be flexible. A flexible design of the lugs limits the radial force acting from the coupling bushing on the roller body, effectively preventing deformation of the roller body.

[0018] The lugs are preferably hollow inside. This makes it possible to compress the lugs radially in order to achieve flexibility. The lugs can, for example, be designed as sheet metal sections that act resiliently to exert a contact pressure on the roller body in the radial direction in order to create a frictional connection between the coupling bushing and the roller body. In this aspect in particular, it is preferred that the lugs have a known spring constant that is set in a predefined manner. This makes it possible, even with certain tolerance deviations, to provide a radial contact pressure within a defined range that is high enough to achieve torque transmission from the coupling bushing to the roller body, to displace oil, but at the same time to prevent deformation of the roller body.

[0019] According to a further preferred embodiment, the output section is welded to the inner circumferential surface of the roller body. According to the invention, this welding is only provided at specific points in order to enable the point-acting, material-to-material transfer of torque from the coupling bushing to the roller body. The output section is preferably connected to the inner circumferential surface of the roller body by spot welding. Roller bodies are usually provided with a zinc layer, which is damaged by high heat input. With spot welding, the heat input is very low. This enables a material-to-material connection of the coupling bushing to the roller body without changing the microstructure topology or the visual appearance of the galvanization on the outside of the roller body. This is achieved in particular by the minimal energy and thus heat input during spot welding.Laser spot welding is particularly preferred because it allows the energy and heat input to be kept particularly low.

[0020] For example, a spot weld connection is provided in the area of ​​the radial lugs. Due to the preload, the radial lugs are permanently in contact with the inner peripheral surface, making these sections particularly suitable for a material-to-material connection using spot welding. Even with certain dimensional deviations, a good contact between the coupling bushing and the inner peripheral section is achieved in these sections, allowing spot welding.

[0021] In a further preferred embodiment, 3 to 20, preferably 5 to 15, particularly preferably 7 to 10 separate connection points are provided around the circumference of the output section, at which the coupling bushing is connected at specific points to the inner circumferential surface of the roller body. It has been found that a number in the range of 3 to 20, and particularly preferably 7 to 10, connection points is sufficient to achieve good torque transmission and, at the same time, also absorb forces acting axially, perpendicular to the rotational axis of the roller body. In relation to the preferred embodiment described above, this means that 3 to 20 lugs and / or 3 to 20 weld points are provided. The individual separate connection points are preferably evenly distributed around the circumference. The exact number depends on the torque to be transmitted and also the diameter of the roller body.

[0022] According to the invention, the coupling bushing is composed of two or more parts and has a radially outer part, which forms the output section, and a radially inner part, which forms part of a shaft-hub connection and is connected to an output shaft of the drive. Because the inner part forms part of a shaft-hub connection, it can be connected particularly easily to the output shaft of the drive. For example, the output shaft of the drive has a polygonal profile, and the inner part of the coupling bushing has an internal polygon that corresponds to the external polygon of the output shaft of the drive. Other preferred shaft-hub connections are keyway connections, clamp connections, and the like. A toothed connection is also conceivable and preferred.In this embodiment, the inner part is preferably connected to the outer part to ensure torque transmission from the inner part to the outer part. The inner and outer parts can be elastically connected to each other to compensate for drive jolts, other shocks, or vibrations.

[0023] In a preferred embodiment, the radially outer part is formed as a corrugated sheet metal strip, in a particularly preferred embodiment from spring steel. Such a corrugated sheet metal strip can, for example, be placed on a substantially cylindrical circumferential surface of the inner part. The radially outer part is preferably placed on the circumferential surface in a prestressed manner and, when pressed into the roller body, is pressed such that the radially outer part is frictionally connected to both the circumferential surface of the inner part and the roller body, in order to be able to transmit torque from the radially inner part via the radially outer part to the roller body.

[0024] In addition, it is also preferable to provide, for example, a positive-locking anti-rotation device to secure the radially outer part against rotation relative to the radially inner part. Such an anti-rotation device can allow a certain degree of rotation as long as it engages after a certain rotation (especially a few degrees) and prevents further rotation. The anti-rotation device should be effective in particular when a frictional connection between the inner and outer parts is insufficient, for example, when high torques are to be transmitted.

[0025] In one embodiment, the anti-rotation device is designed as a stop against which a circumferential end section of the radially outer part abuts. In this case, the anti-rotation device acts in a form-fitting manner. Alternatively or additionally, a materially bonded anti-rotation device is also conceivable and preferred. For example, the radially outer part can be attached to the radially inner part by means of one or more weld points. It is also conceivable for the radially outer part to be connected in a form-fitting manner to the radially inner part by means of a pin connection.

[0026] According to the invention, the radially inner part is made of a flexible material, in particular an elastomer material. This makes the shaft-hub connection between the inner part and the drive's output shaft elastic in the direction of rotation, so that jolts or other loads can be cushioned. Another advantage here is the manufacturing tolerance, since elastic components, due to their material properties, can compensate for manufacturing tolerances better than rigid elements.

[0027] In an advantageous embodiment, the coupling bushing is mounted so as to be axially displaceable relative to the drive unit. Preferably, the hub is also mounted so as to be axially displaceable. Preferably, no additional axial fixation, such as a front-end screw for fixing the hub, is provided. Preferably, at least the hub is mounted on the output shaft of the drive by means of an axial loose bearing, or the coupling bushing is mounted on the hub by means of an axial loose bearing. This allows for axial relative displacement between the coupling bushing and the drive unit. On the one hand, this is preferred to compensate for tolerances, and on the other hand, it is made possible by the connection between the coupling bushing and the roller body.

[0028] According to a further embodiment, the coupling bushing has a central recess into which an output shaft of the drive is inserted, wherein the central recess has circumferentially alternating radially extending projections and recesses. The recess can be formed in the inner part of the coupling bushing and form part of the shaft-hub connection. The recess is preferably designed as a through-opening. According to this embodiment, the central recess has a substantially star-shaped contour in cross-section, which further allows for compensation of manufacturing tolerances. The inner part or the coupling bushing is slightly flexible due to the star-shaped inner recess and is thus able to compensate for small manufacturing tolerances.A further advantage is that the star-shaped contour can also be used for the positive transmission of torque from the drive output shaft to the coupling bush.

[0029] In a preferred embodiment, the projections are concavely flattened at their radially inner tips. This allows for contact with essentially cylindrical sections of an output shaft of the drive.

[0030] The coupling bushing preferably has axial recesses in the region of the radial projections. The axial recesses extend partially in the axial direction through the coupling bushing; preferably, the recesses extend completely through the coupling bushing. Particularly preferably, the recesses have a substantially trapezoidal cross-section. Preferably, the cross-section of the recesses corresponds to the cross-section of the projections, so that an approximately uniform wall thickness results between the recess in the projection and the central recess. Such recesses achieve weight and material savings, and the projections are further flexible and capable of absorbing jolts or other load peaks.

[0031] Furthermore, it is preferred that the lateral flanks of the radial projections are substantially radially aligned. As a result, the flanks of the radial projections provide contact surfaces for torque transmission, and a force from the drive's output shaft to the coupling sleeve acts perpendicularly on the flank of the projections when the drive drives the coupling sleeve.

[0032] According to the invention, the coupling bushing has an axially extending collar on which the output section is formed. The axially extending collar extends axially away from the inner part and is preferably formed on the outer part. The collar preferably has a diameter that is larger than the diameter of the axially adjacent section of the coupling bushing. This also further compensates for manufacturing tolerances. This embodiment is particularly preferred when the output section is integrally connected to the roller body. In this case, the axially extending collar can be formed from a thin sheet metal section that can be easily connected to the roller body by spot welding, in particular by laser spot welding.

[0033] The invention is explained in more detail below using exemplary embodiments.

[0034] Showing: Fig. 1a cross-section through a conveyor roller; Fig. 2an enlarged cross-section of the conveyor roller from Fig. 1 ; Fig. 3 a cross section according to Fig. 2 of a first embodiment; Fig. 4 a side view of a coupling bush according to the first, not claimed, example; Fig. 5 a cross section AA according to Fig. 4 ; Fig. 6Detail A from Fig. 4 ; Fig. 7Detail B from Fig. 4 ; Fig. 8 a perspective view of a coupling bushing according to a second embodiment; Fig. 9 a side view of a coupling bushing according to a third embodiment; Fig. 10 a perspective view of a hub for the coupling bushings according to Fig. 2 and 4 to 9 ; Fig. 11 a section through the hub according to Fig. 10 ; Fig. 12 a perspective view of a coupling bushing according to the first embodiment; Fig. 13 a section through the coupling bushing from Fig. 12; Fig. 14 a perspective view of a coupling bushing according to a fourth embodiment including hub according to. Fig. 10 ; and Fig. 15 a further perspective view of the coupling socket according to the fourth embodiment.

[0035] Fig. 1 shows the basic structure of a motor-driven conveyor roller 1 according to the invention. An end cap 4 is inserted into the roller body 2 at a first end 3, which is firmly connected to the roller body 2 and within which a rolling bearing 6 is arranged.

[0036] The rolling bearing 6 serves to rotatably support a bearing journal 8. The bearing journal 8 is provided with an external thread at an outward-facing end, onto which a nut 10 is screwed, allowing the bearing journal 8 to be torque-tightly secured in an opening of a frame. The frame is clamped between the nut (not shown) and a sleeve secured on the thread 10 inward of the nut.

[0037] The roller body 2 has an inner circumferential surface 12 which radially outwardly delimits an interior space 14 in the roller body 2.

[0038] The bearing journal 8 is hollow, and supply and control lines 16 are routed through the inner bore of the bearing journal 8 to a drive unit 18 arranged inside. The drive unit 18 is arranged within the roller body 2 and is connected to the bearing journal 8 in a torque-resistant manner. The drive unit 18 has, at its end facing the bearing journal 8, control electronics 20 for controlling an electric drive motor 22, which is preferably designed as a brushless, three-phase DC motor with an internal rotor. The drive motor 22 is arranged between the control electronics 20 and a planetary gear 24 in the drive unit 18, which is arranged at the end of the drive unit 18 facing away from the bearing journal 8.

[0039] The planetary gear 24 has an output shaft 26, which in turn is mounted in a roller bearing 28.

[0040] To transmit torque from the output shaft 26 to the roller body 2, the conveyor roller 1 has a coupling unit 30, which will be explained in more detail below. As a result of the transmission of torque from the output shaft 28 via the coupling unit 30 to the roller body 2, the roller body rotates with the drive torque relative to the bearing journal 8 and the drive unit 18.

[0041] At the end 5 of the roller body 2 opposite the bearing journal 8, a head piece 32 is inserted into the roller body 2 in a torque-resistant manner. This head piece 32 has several W-shaped circumferential grooves 34, by means of which the rotation and torque of the conveyor roller 1 can be transmitted to adjacent idler rollers. Within the head piece 32, a receptacle 36 for a rolling bearing is formed for supporting the conveyor roller 1 on an end bearing journal (not shown).

[0042] Fig. 2now shows the outbreak B from Fig. 1 An enlarged view. The clutch unit 30 is shown, which is mounted on the output shaft 26. The clutch unit 30 has a hub 40, which is mounted against the output shaft 26 by means of a screw 42. For this purpose, the output shaft 26 has a blind bore 44 provided with an internal thread. The hub 40 rests with a front end 46 against the roller bearing 28 when it is axially fixed to the output shaft 26 with the screw 42, as in the illustrated embodiment.

[0043] Radially outwardly, the hub 40 has a substantially cylindrical basic shape, which is provided with radial projections 48a, 48b.

[0044] On the hub 40 (see also Figs. 10 and 11 ) is according to this first example, which is not part of the invention, ( Fig. 2) a coupling bushing 50 is provided, which is formed as a single piece. The coupling bushing 50 has an output section 52, which in this exemplary embodiment is connected to the inner circumferential surface 12 of the roller body in a frictionally engaged manner at certain points to transmit torque. For this purpose, the coupling bushing 50 has a plurality of radial lugs 54 that are in contact with the inner circumferential surface 12.

[0045] More precisely, the lugs 54 together define a diameter D1 that is slightly larger than the diameter D2, which is the inner diameter of the roller body 2. The individual lugs 54 are designed to be slightly resilient, so that they can be elastically deformed, in particular so that the diameter D1 is reduced. In this way, the coupling bushing 50 can be arranged axially in the interior 14 of the roller body 2, with the lugs 54 elastically exerting a radial force on the inner circumferential surface 12, thus achieving a frictional connection between the coupling bushing 50 and the roller body 2.

[0046] According to this example, the coupling bushing 50 further includes a web 56 that extends radially at one axial end of the output section 52, but has a diameter smaller than the diameter D2. The web 56 does not serve to transmit torque, but solely to position the coupling bushing 50.

[0047] In Fig. 3 An embodiment of the invention is shown. Identical and similar elements are provided with the same reference numerals, and reference is made to the above description in its entirety. Fig. 2 and 1 Reference is made.

[0048] Fig. 3 also exhibits outbreak B Fig. 1 , in which case a different coupling bushing 50 is used.

[0049] The coupling bushing 50 sits on the hub 40, which in turn is designed like the hub 40 according to the first example ( Fig. 2 ) is provided with radial projections 48c, 48d. According to this embodiment ( Fig. 3 ) the coupling bush 50 is in two parts and is mounted with reference to the Figs. 10 and 11will be explained in more detail. In this exemplary embodiment, the coupling bushing 50 has a radially outer part 60 and a radially inner part 62, wherein the radially inner part 62 is formed from a flexible material, in particular a plastic or elastomer. The outer part 60 has the output section 52, which according to this exemplary embodiment is designed as an axially extending collar. The collar 64 of the output section 52 is formed from a thin-walled sheet metal material which, in particular, has a smaller thickness than the roller body 2. According to this exemplary embodiment, the thickness of the collar 64 is approximately half the thickness of the roller body 2, in particular 40%, 30% or less.

[0050] In this exemplary embodiment, the coupling bushing 50 is connected to the roller body 2 via a material-to-material connection. For this purpose, several welding points 66a, 66b are provided, which connect the collar 64 to the inner circumferential surface 12 of the roller body 2. The individual welding points 66a, 66b can be formed slightly axially offset from an axial end of the collar 64, as shown in the case of welding point 66a, or directly at the axial end, as shown in the case of welding point 66b. In this way, manufacturing tolerances and inaccuracies of the collar 64 and the roller body 2 can be compensated for. The collar 64 is formed from a relatively thin sheet material and can thus also be easily compressed radially. This enables the insertion of the coupling bushing 50, even if the collar 64 slightly oversizes the diameter of the roller body 2.However, since the collar 64 is made of a relatively thin sheet material, it is not capable of providing a sufficient force-fitting press connection between the coupling bushing 50 and the roller body 2. Therefore, to transmit torque, the collar 64 is integrally connected to the roller body 2 at a plurality of individual welding points.

[0051] To create the welding points, a laser device is preferably positioned from the outside at the end of the pipe and for welding, the laser beam is focused at the desired points inside the pipe in order to melt the components to be joined at specific points.

[0052] It should be understood that the example of Fig. 2 and the embodiment of the Fig. 3 can also be combined and only their structure is initially in the Fig. 2 and 3represent various alternatives. It is also preferred to additionally connect the individual lugs 54 to the inner circumferential surface 12 of the roller body 2 via welding points 66a, 66b in order to achieve even more effective torque transmission.

[0053] In the Fig. 4 to 13 the coupling bushings 50 are shown separately and explained in more detail according to the various examples and embodiments.

[0054] Fig. 4 shows first a coupling bushing 50, as it is basically also shown in the example according to the Fig. 1 and 2 is installed. Fig. 5 shows the cross section AA from Fig. 4 , and in the following both figures will be discussed equally.

[0055] As already mentioned with reference to Fig. 2As described above, the coupling bushing 50 has an output section 52 and a plurality of radial lugs 54 arranged thereon. According to this embodiment, a total of seven lugs 54 (in Fig. 4 only two are provided with reference numerals) are evenly distributed around the circumference. The lugs 54 together define a diameter D1 (see Fig. 5 ), which is slightly larger than the diameter D2 of the roller body 2. The noses 54 have in cross section (cf. Fig. 4 ) have a spherical profile and feature two essentially flat flanks 68a, 68b, as well as a rounded tip 70. Due to this design, the lugs 54 are somewhat elastic overall, in that they can expand in the circumferential direction through radial compression. This makes it possible to compensate for tolerances while still establishing a good frictional connection between the coupling bushing 50 and the roller body 2.

[0056] In the axial direction, the lugs 54 also have spherical insertion surfaces 72a, 72b, so that joining of the coupling bush 50 in the axial direction into the interior 14 of the roller body 2 is easily possible.

[0057] Radially inward, the coupling bushing 50 has a central recess 74, which is designed as a through-hole. By means of this recess 74, the coupling bushing 50 can be pushed onto the hub 40 in the axial direction. The inner circumferential surface 76 of the central recess 74 has a contour that allows a positive connection in the direction of rotation between the hub 40 and the coupling bushing 50. For this purpose, a plurality of projections 78 and recesses 80 are provided on the central recess 74 (in Fig. 4 only one is provided with a reference number), which are distributed evenly around the circumference of the central recess 74.

[0058] According to this embodiment, axial recesses 82 are provided in the area of ​​the projections 78 (cf. Fig. 6 ). These axial recesses 82 point in cross-section perpendicular to the rotation axis of the coupling bush 50 (i.e. in the plane of the drawing according to Fig. 6 ) has a substantially trapezoidal shape. Its tip 83 substantially corresponds to the contour of the projection 78, so that a wall 84 separating the axial recess 82 from the central recess 74 in the region of the projections 78 has a substantially constant wall thickness.

[0059] The projections 78 have a concave contour 86 radially inward at the tips.

[0060] The lateral flanks 88a, 88b of the projections 78 are essentially radially aligned. This results in the recesses 80 widening slightly radially outward and terminating in a concavely shaped bottom 90. In particular, the radial alignment of the lateral flanks 88a, 88b results in the radial projections 48a, 48b on the hub 40 coming into contact with the flanks 88a, 88b, and a force from the projections 48a, 48b acting essentially perpendicularly on the flanks 88a, 88b.

[0061] The axial recesses 82 lead on the one hand to a weight reduction, on the other hand they explicitly serve the slightly elastic design of the projections 78, which serves to cushion jerks and other load peaks.

[0062] The Figs. 8 and 9 illustrate a second embodiment, which is similar to the first example. According to the second embodiment ( Figs. 8 and 9), the coupling bushing 50 is formed in two parts. It has a radially inner part 62 and a radially outer part 60, which forms the output section 52.

[0063] The inner part 62 has a substantially cylindrical peripheral surface 92, onto which the outer part 60 is applied in the form of a corrugated sheet metal strip. The corrugated sheet metal strip of the outer part 60 forms a plurality of lugs 54, which in this embodiment are hollow and define a cavity 94 within. This further enhances the elasticity of the lugs 54, and manufacturing tolerances can be compensated even more effectively.

[0064] Fig. 9shows a slightly modified embodiment in which not only trapezoidal recesses 82 are formed in the region of the projections 78, but also essentially rectangular axial recesses 96 in the region of the recesses 80. This leads to further weight reduction and also to a further elastic design of the coupling bushing 50.

[0065] A hub 40, as it is provided with the coupling bushings 50 according to the described embodiments from the Figures 2 , and 4 to 9 can be used, will now be described in more detail with reference to the Figures 10 and 11 described. The hub 40 according to the Figures 10 and 11has an inner hub portion 41, which is preferably formed from a substantially rigid material, in particular a wear-resistant plastic such as polyamide. The inner hub portion 41 has a central recess 43, via which the hub 40 can be connected to the corresponding portion of the output shaft 26. The central recess 43 has a first portion 43a with an internal polygon and a stop ring 43b. The internal polygon cooperates with the corresponding external polygon of the output shaft 26 for torque transmission. The stop ring 43b serves for axial positioning.

[0066] The hub 40 further comprises an outer portion 45 which radially and circumferentially surrounds the inner portion 41 and is preferably formed from a resilient material, such as an elastomer material. The outer portion 41 defines the projections 48a, 48b, 48c, 48d (in the Figures 10 and 11(Not all projections are provided with a reference numeral.) Internally, the projections 48a, 48b, 48c, 48d are each supported by a web 47a, 47b, 47d formed on the inner part 41 and extending radially therefrom. The webs 47a, 47b, 47d provide reinforcement for the projections 48a, 48b, 48c, 48d.

[0067] At a first axial end, the projections 48a, 48b, 48c, 48d each have a radial tongue 49a, 49b, 49d, which together define a collar having a diameter D4 larger than the diameter D3 of the projections 48a, 48b, 48c, 48d. The purpose of the tongues 49a, 49b, 49d is to prevent the hub 40 from "wandering out" during operation if it is not secured by a screw 42. The hub 40 is arranged with the section 43a on the output shaft 26. The coupling bushing 50 is then pushed on and rests against the tongues 49a, 49b, 49d with its end face facing the drive. The drive and the coupling bushing 50 are in turn axially fixed; the drive via the end cap 4 and the coupling bushing 50 via its connection to the roller body 2. This also axially fixes the hub 40 and prevents it from "wandering out", even though it has a loose bearing and is not clamped by a screw 42.

[0068] The Figs. 12 and 13 illustrate another embodiment of the coupling bushing as shown in Fig. 3 The coupling bushing is shown in the Figs. 12 and 13 is again two-part and has an inner part 62 and an outer part 60. The inner part 62 is made of a plastic or elastomer material to compensate for jerks or other load peaks. The output section 52 is here, as already described with reference to Fig. 3described, is designed as a collar 64 which extends away from a section 98 enclosing the inner part 62. While the section 98 forms a radially outer shell for the flexible inner part 62, the collar 64 is formed from a relatively thin sheet material which can be easily joined to the roller body 2 by spot welding. The axial extension of the collar 64 serves, on the one hand, to keep the collar 64 flexible in order to be able to both radially expand and radially reduce it in order to compensate for manufacturing tolerances. On the other hand, this also provides a spatial distance between the welding points and the inner part 62 in order to prevent heating of the flexible inner part 62. The use of laser spot welding further enhances this effect.

[0069] The inner part 62, corresponding to the first exemplary embodiments, has a central recess 74 with an inner contour 76 that is approximately star-shaped. This contour 76 also has projections 78 and recesses 80 that are equally distributed around the circumference. The alternating recesses 80 and projections 78 serve to enable a positive transmission of force and torque from the hub 40 to the coupling bushing 50.

[0070] The Figures 14 and 15 show a further embodiment of the coupling bushing 50. Basically, this embodiment is similar to the second third embodiment ( Fig. 8) and the coupling bushing 50 is formed in two parts with a radially outer part 60, which defines the output section 52, and a radially inner part 62. The radially outer part 60 is in turn formed as a corrugated sheet metal strip that sits on a substantially cylindrical peripheral surface 92 of the radially inner part 62.

[0071] The corrugated sheet metal strip has a radial gap 99, which is delimited by a first end section 104 and a second end section 105. This gap 99 is also present in the sheet metal strip of the third embodiment ( Fig. 8 ). It serves to more easily adapt the sheet metal strip to the diameter of the radially inner part 62.

[0072] The radially inner part 62 has, as already shown in the first embodiment ( Fig. 5), has a web 56 which has a larger diameter than the circumferential surface 92 and thus serves for the axial positioning of the radially outer part 60.

[0073] In order to prevent rotation of the radially outer part 60 relative to the radially inner part 62, according to these embodiments ( Figs. 14, 15 ) an anti-rotation device 100 is provided. According to these embodiments, the anti-rotation device 100 has a stop 102 against which one of the first and second end sections 104, 105 can strike. The stop 102 is located within the gap 99, but has a smaller circumferential extent, so that a certain rotation of the radially outer part 60 is permitted until the first or second end section 104, 105 comes into contact with the stop 102.

[0074] Circumferential end faces 106, 107 (cf. Fig. 14) of the stop 102 are radially aligned so that they provide a flat contact surface for the end sections 104, 105. This provides secure contact, which can prevent the radially outer part 60 from becoming loose and axially displacing away from the web 56. The diameter or radial extension of the stop 102 is equal to or less than that of the web 56 to enable easy assembly.

[0075] Instead of the stop 102, however, a purely material-locking anti-twist device is also conceivable, for example by providing one or more welding points to connect the sheet metal strip to the circumferential surface 90.

[0076] For illustrative purposes, the hub 40 of the Fig. 10 The recesses 82 are in this embodiment ( Figs. 14, 15 ) are designed as blind hole-like recesses, so that the axial front side in Fig. 15This allows for material savings (mass inertia / costs) and achieves nearly constant wall thicknesses, which are advantageous for cast / injection-molded parts.

Claims

1. A motor-driven conveyor roller (1) for conveyor systems for conveying containers, pallets and the like, with - a roller body (2), the outer circumferential surface of which constitutes a support surface for conveyed goods, - a drive unit (18) arranged within an interior (14) of the roller body (2), - a coupling unit (30) designed for transmitting a torque from the drive unit (18) to an inner circumferential surface (12) of the interior (14) of the roller body (2), which - has a clutch bushing (50), which has a drive section connected with the drive unit (18) and an outer peripheral output section (52), wherein the clutch bushing (50) is of two or more parts, and has a radially outer part (60) that defines the drive section (52) and a radially inner part (62) that forms part of a shaft-hub connection and is connected with an output shaft (26) of the drive, wherein the radially inner part (62) consists of a flexible material, in particular an elastomer material, characterized in that the clutch bushing (50) is only frictionally connected at certain points with the inner circumferential surface (12) of the roller body (2) for transmitting torques.

2. The conveyor roller according to claim 1, wherein the output section (52) of the clutch bushing (50) has a plurality of radial noses (54), which are provided for being in contact with the inner circumferential surface (12) of the roller body (2).

3. The conveyor roller according to claim 2, wherein the radial noses (54) together define a diameter (D1) that is larger than the diameter (D2) of the inner circumferential surface (12).

4. The conveyor roller according to claim 3, wherein the noses (54) are flexible and preferably internally hollow in design.

5. The conveyor roller according to one of the preceding claims, wherein 3 to 20, preferably 5 to 15, especially preferably 7 to 10 separate connecting points (54, 66a, 66b) are provided around a circumference of the output section (52), on which the clutch bushing (50) is connected at certain points with the inner circumferential surface (12) of the roller body (2).

6. The conveyor roller according to one of the preceding claims, wherein the radially outer part (60) is designed as a corrugated metal strip.

7. The conveyor roller according to claim 6, wherein the radially inner part (62) has an essentially cylindrical circumferential surface (92), upon which the outer part (60) is placed.

8. The conveyor roller according to one of the preceding claims, having an anti-twist device (100) to secure the radially outer part (60) against rotation relative to the radially inner part (62), in particular a positive locking anti-twist device, wherein the anti-twist device (100) is preferably designed as a stop (102), which is impacted by a circumferential end section (104, 105) of the radially outer part (60).

9. The conveyor roller according to one of the preceding claims, wherein the clutch bushing (50) is axially movably mounted relative to the drive unit (18).

10. The conveyor roller according to one of the preceding claims, wherein the clutch bushing (50) has a central recess (74), in which an output shaft (26) is placed, wherein the central recess (74) has alternating, radially extending projections (78) and recesses (80) around the circumference, wherein the projections (78) are preferably concavely flattened on the radially inner tips (86), and wherein lateral flanks (88a, 88b) of the radial projections (78) are preferably essentially radially aligned.

11. The conveyor roller according to claim 10, wherein the clutch bushing (50) has axial recesses (82) in the area of the radial projections (78), wherein the axial recesses (82) preferably have an essentially trapezoidal cross section.

12. The conveyor roller according to one of the preceding claims, wherein the clutch bushing (50) has an axially extending collar (64), on which the output section (52) is formed.

13. A motor-driven conveyor roller (1) for conveyor systems for conveying containers, pallets and the like, with - a roller body (2), the outer circumferential surface of which constitutes a support surface for conveyed goods, - a drive unit (18) arranged within an interior (14) of the roller body (2), - a coupling unit (30) designed for transmitting a torque from the drive unit (18) to an inner circumferential surface (12) of the interior (14) of the roller body (2), which has a clutch bushing (50), which has a drive section connected with the drive unit (18) and an outer peripheral output section (52), wherein the clutch bushing (50) is only frictionally connected at certain points with the inner circumferential surface (12) of the roller body (2) for transmitting torques. wherein the clutch bushing (50) consists of two or more parts, and has a radially outer part (60) that defines the drive section (52) and a radially inner part (62) that forms part of a shaft-hub connection and is connected with an output shaft (26) of the drive, wherein the clutch bushing (50) has an axially extending collar (64) on which the drive section (52) is formed, characterized in that the collar (64) extends axially away from a section (98) jacketing the inner part (62), and is only bonded at certain points with the inner circumferential surface (12) of the roller body (2) for transmitting torques.