Roller bearing assembly with curved rail

Abstract

The invention relates to a system for guiding at least one object on a curved rail (1) with a guide profile which has inner and outer running tracks (17a; 17b) with respect to a radius of curvature of the curved rail (1), said system comprising a carrier (4) which is displaceable along the curved rail (1) in the displacement direction and is mounted on running rollers (2, 3). At least three running rollers (2, 3) are arranged one behind the other in the displacement direction of the carrier (4). At least one first running roller (2) is arranged offset with respect to a second running roller (3) transversely to the displacement direction, with the result that the running rollers (2, 3) are each in engagement either with the inner running track (17a) or with the outer running track (17b) of the guide profile.

Description

[0001] May 5, November 2025

[0002] Applicant: igus GmbH, 51147 Cologne

[0003] Roller bearing assembly with curved rail

[0004] The invention relates to a system for guiding at least one object at least on a part of a circular path, comprising at least one curved rail with at least one guide profile.

[0005] A system for guiding along a curved guide rail is known, for example, from DE 20 2016 101 698 Ul. This publication describes a sliding bearing for guiding on a double guide rail, which has an elongated rail body and a guide profile on both longitudinal sides. The sliding bearing comprises a slide having at least three bearing receptacles, each forming a through-opening and having a sliding element arranged in the through-opening, forming a continuous sliding opening for the guide profile. To ensure the sliding bearing's ability to navigate curves, the sliding bearing according to DE 20 2016 101 698 Ul is designed so that each sliding element is rotatably mounted in the corresponding bearing receptacle about at least one principal axis, which lies perpendicular to a plane perpendicular to the sliding axis of the sliding opening of the sliding element.This sliding bearing is particularly suitable for use with guide rails that have a multiply curved track. For guiding a curved track, roller guides are also known from the prior art. Roller guides can be designed so that a carriage or carriage can be guided not only linearly but also along one or more curves defined by the rail, with the curved track lying in a plane.

[0006] Compared to plain bearing guides, roller guides have the disadvantage of requiring more maintenance. In contrast, plain bearings can generally be operated without the application of lubricants and consequently require relatively little maintenance. On the other hand, roller guide bearings are characterized by particularly low-friction operation.

[0007] Not all industrial applications, such as sorting carousels or the like, require guiding an object on a multiply curved circular path or a circular path with a non-constant radius, i.e., a non-constant radius of curvature, so that the amount of curvature varies.

[0008] The invention is based on the objective of providing a system of the type mentioned above which enables low-friction and therefore quiet and simple guidance on at least part of a circular path and which in particular ensures backlash-free guidance.

[0009] The problem underlying the invention is solved by providing a system with the features of claim 1.

[0010] Advantageous embodiments of the invention are covered by the dependent claims.As a solution to the described problem, the invention proposes a system for guiding at least one object at least on a part of a circular path or around an axis of rotation, the system comprising at least one curved track with at least one guide profile, which has at least two inner and outer running tracks extending at least over a partial circular arc and with respect to a radius of curvature of the curved track, comprising at least one support that is displaceable along the curved track in a displacement direction for receiving the at least one object, wherein the support is mounted on a plurality of rollers, wherein at least three rollers, preferably exactly three rollers, are arranged one behind the other in the displacement direction of the support and at least one first roller is positioned transversely to the displacement direction along the circular path with respect to at least one second roller.is arranged radially offset, so that the running rollers, with respect to the radius of curvature of the curved rail, are each either on the inside or on the outside in contact with a running track, i.e., each is in contact with the inner running track or with the outer running track.

[0011] The respective roller is positioned in a ready-to-use state for rolling on the inner or outer track.

[0012] In this way, low-friction and backlash-free guidance of the carrier along the curved track is ensured.

[0013] Furthermore, it is ensured that each of the rollers is only engaged with the curved track on one side, so that the rollers can roll without slippage on one track of the guide profile each, and in particular, tilting of the beam about a vertical axis is prevented. The term "vertical axis" refers to an axis perpendicular to the direction of displacement along the circular path.

[0014] The curved rail can extend in a plane that can have any angular orientation in space. That is, the curved rail can be designed and configured for horizontal as well as vertical mounting on or to a mounting surface.

[0015] Within the scope of the invention, it is irrelevant whether the support is displaced relative to the curved track or whether the support is fixed in place and the curved track is rotatable relative to a support. Both variants are intended to be covered by the invention. For example, within the scope of the invention, several roller-bearing supports can be provided that are fixed in place, whereas the curved track can fulfill the function of receiving an object that is rotatably mounted.

[0016] Preferably, the curved rail is designed for fixed installation, whereas at least one support is guided in a movable manner on the curved rail.

[0017] The system according to the invention is designed for a given, selectable guide length. The guide length can extend over a closed circular arc or only over a partial segment / partial circumference of a circular arc. The guide length can be defined either by the circumference and radius of the curved track or by corresponding stops to limit the displacement path of the at least one support.

[0018] It is generally preferred that the radius of curvature of the curved track has such a profile over the entire guide length of the curved track that the rollers, during displacement over the entire guide length, either remain in continuous contact with the curved track or maintain a constant clearance to the curved track over the entire guide length. Providing continuous contact, particularly with pressure against the curved track in the radial direction or in the direction perpendicular to the displacement direction, has proven to be particularly advantageous. This can be advantageously achieved, for example, by ensuring that the curved track, and thus the displacement direction, has a constant radius of curvature, or by ensuring that the rollers are positioned in an adjustment direction perpendicular to the direction of travel.The cam profile runs radially in the direction of displacement, and thus in the radial direction with respect to the radius of curvature. The cam profiles are adjustable relative to each other, as explained above, in advantageous embodiments, with the variation of the radius of curvature over the entire guide length being adapted to the adjustability of the cam profiles relative to each other. By providing a constant radius of curvature, the cam profiles can be arranged in a particularly simple manner, either maintaining continuous contact with the cam profile over its entire guide length or exhibiting constant clearance relative to the cam profile over its entire guide length, since the arrangement of the cam profiles relative to each other can be specifically adapted to the radius of curvature.

[0019] By incorporating a changing radius of curvature, specific system requirements can be met. Furthermore, allowing for changes or variations in the radius of curvature while considering the adjustability of the rollers relative to each other, or providing adjustability of the rollers relative to each other adapted to the variation in the radius of curvature, can advantageously ensure that the rollers maintain continuous contact with the track or exhibit constant clearance along the entire guide length of the track. For example, suitable means can be provided to ensure adjustability of the rollers adapted to variations in the radius of curvature, such as a mechanical coupling of the rollers' relative positions depending on the radius of curvature.The mechanical coupling can be ensured, for example, by a spring device and / or a force-lever mechanism and / or an adjustable guide with an inclined plane.

[0020] In general, the adjustability of the rollers relative to each other refers to adjustability in an adjustment direction that runs perpendicular or transverse to the displacement direction.

[0021] It is generally preferred that at least one of the rollers is adjustablely supported on a body of the carrier by a spring device transverse to the direction of displacement.

[0022] The curvature of the curved track is particularly preferably located in a single plane.

[0023] The at least one support can, for example, be configured to receive an object to be moved along a circular path or part of a circular path. The configuration or design of the object can be arbitrary and is not critical to the invention.

[0024] A particularly preferred embodiment of the system according to the invention provides for means of adjusting at least one roller in the displacement direction of the carrier and / or at an angle to the displacement direction of the carrier greater than 0°, preferably radially and / or circumferentially along the circular path, particularly for adapting to a given radius of the curved track and / or for adjusting bearing clearance. The means can, for example, comprise at least one spring assembly, at least one actuating drive, at least one eccentric, and / or at least one adjustment guide with a plane inclined to the displacement direction.

[0025] It is particularly preferred that at least one roller is adjustably arranged on the support along an adjustment direction transverse to the displacement direction of the support by an offset dimension or axial offset. Preferably, a leading and a lagging roller, as well as a middle roller arranged between them, are provided, wherein the axial offset is generally preferably defined by the radial distance of the center of the axis of the middle roller from a straight line passing through the centers of the axes of the leading and lagging rollers, wherein the straight line and the segment for determining the radial distance, which thus extends radially from the straight line to the axis of the middle roller and is perpendicular to the straight line, lie in a plane.

[0026] In this application, the term "radial" refers to the radius of curvature of the curved track. A radial distance is thus defined as the distance from the center point around which the curve is formed. Accordingly, the outer track is naturally further from the center point around which the curve is formed than the inner track. The preferred adjustability ensures that a roller-bearing support for the object to be moved can be adapted to different curve radii. This offers particular manufacturing advantages, as it eliminates the need to provide a specially designed support for each curve radius. Furthermore, the bearing clearance of the roller bearing formed by the rollers can be adjusted via the offset or axial offset of the rollers.

[0027] In this context, it can be particularly advantageous from a design perspective if at least one adjusting mechanism is provided, with which an offset of the rollers or the axle offset in an adjustment direction transverse to the displacement direction of the support can be set. It has generally proven advantageous to provide such displacement or adjustability of at least one roller by means of such means that the course of the curved track and thus the course of the displacement direction over the entire guide length of the guide rail is adapted to it.

[0028] Preferably, the means comprise a spring device by which a spring-elastic displacement capability or .

[0029] The adjustability of at least one roller relative to at least one other roller, in particular the at least one second roller described here relative to the at least one first roller, is ensured. The spring mechanism ensures that in every position along the direction of displacement, all rollers are always held perpendicular to the direction of displacement by the spring mechanism against the track, in particular pressed against it.

[0030] The system according to the invention expediently comprises exactly three rollers provided on a support, wherein the rollers, with respect to the direction of displacement of the support, comprise at least two first rollers, namely a leading first roller and a lagging first roller, and a second roller arranged between the first rollers. That is to say, in each direction of displacement, one of the first rollers is a leading roller and another of the first rollers is a lagging roller.

[0031] Preferably, the second roller has an axis that is adjustable along the adjustment direction transversely to the intended displacement direction or radially with respect to the radius of curvature via a feed path, via which the offset dimension or the axis offset can be adjusted.

[0032] The radius of curvature of the curved track can, for example, range from approximately 300 mm up to and including 4000 mm. Those skilled in the art will recognize that the upper and lower limits for the radius of curvature of the curved track are not sharp boundaries. In principle, the radius can also be larger than 4000 mm, although it would then be barely perceptible as a circular path. Radii tighter than approximately 300 mm are not practical beyond a certain pitch between the running rollers and beyond a certain size of the running rollers, but are not fundamentally impossible.

[0033] Advantageously, the possible delivery path can be chosen such that the radial axis offset of the running rollers, in particular between the middle running roller described here and the leading and trailing running rollers or between the second running roller described here and the first running rollers, can be greater than or equal to 0.2% up to and including 5% of the radius of curvature.

[0034] The axle offset is expediently determined depending on the radius of curvature and on a pitch measurement between the first running rollers.

[0035] The invention relates in particular to a system comprising several different curved rails, which differ in their radii of curvature and which are each designed corresponding to the support. The system can thus have different operating states, each of which is realized by the same support and a different curved rail of the system, by having the same support arranged to be displaceable along a first of the curved rails in a first operating state and arranged to be displaceable along a second of the curved rails in a second operating state of the system, wherein the first curved rail has a larger radius of curvature than the second curved rail and the axis offset in the first operating state is smaller than in the second operating state. With a constant pitch, the axis offset is chosen to be smaller with increasing radius of curvature of the curved rail.Preferably, the radius of curvature of the first curved rail is at least 300% of the radius of curvature of the second curved rail, wherein the axis offset in the second operating state is at least 120% of the axis offset in the first operating state.

[0036] In an advantageous and practical embodiment of the invention, it is provided that the first rollers are spaced apart from each other with a pitch of greater than or equal to 70 mm to less than or equal to 120 mm.

[0037] For example, in an embodiment where the radius of the curved track is approximately 4000 mm and the pitch of the outer rollers, i.e., the leading and trailing rollers, is approximately 70 mm, the axis offset can be approximately 0.15 mm. The pitch, as defined in the present invention, is the distance between the axes (center of axis to center of axis) of the rollers in the direction of displacement of the support or in the direction of the circular path.

[0038] In another embodiment according to the invention, with a radius of the curved track of about 300 mm and a pitch of the outer rollers of about 70 mm, the axle offset can be about 2 mm.

[0039] In another embodiment, with a curve radius of 300 mm and a pitch of the outer rollers of 120 mm, the axis offset can be approximately 6 mm.

[0040] To make adjustment easy, at least one axle of a roller can be displaced or adjusted in a slotted hole of the carrier.

[0041] A spindle drive can be provided as a means of adjusting the axis of the roller, comprising a spindle acting on an axis of the adjustable roller, preferably as a threaded spindle with an external thread.

[0042] The spindle drive preferably comprises a screw drive with a threaded spindle or an adjusting screw which has an external thread.

[0043] The support can have a threaded bore to match the threaded spindle or adjusting screw, for interaction with the threaded spindle or adjusting screw. The threaded bore can extend along the direction of adjustment.

[0044] The external thread of the threaded spindle can interact with the internal thread of the threaded bore in the support to adjust the adjustable axis of the roller along the adjustment direction.

[0045] The threaded spindle can act on the axis of the roller with one end face in order to move the axis along the adjustment direction.

[0046] For this purpose, the end face of the threaded spindle can engage with the adjustable axis. In this design, the threaded spindle, with its end face (for example, with a terminal end), acts on the axis of the roller to move the axis along the adjustment direction. The axis can be moved within the elongated hole in the support until it reaches an end position.

[0047] Advantageously, the spindle drive includes means for locking the spindle in an end position, wherein, in particular, these means include a counter element for locking the spindle or the adjusting screw, or are designed as a counter element. In this way, a predetermined axial offset of the rollers can be set and fixed in such a way that unintentional adjustment is prevented.

[0048] The counter element is preferably designed as a screw with a screw thread. The axle of the roller or the support can have a receptacle facing the threaded spindle with a thread corresponding to the screw thread of the counter element, wherein, to lock the threaded spindle in the end position, the screw can be screwed into the corresponding thread in such a way that it exerts a clamping force against the threaded spindle.

[0049] In one embodiment, a setscrew is used as the counter element for locking the threaded spindle or the adjusting screw, whereby the setscrew can be screwed into the threaded bore of the support from a different, opposite side than the threaded spindle or the adjusting screw.

[0050] In one embodiment, a locking screw, preferably with a head, is used as a counter element to secure the threaded spindle or adjusting screw. The threaded spindle may have an open passage for the locking screw to receive the shaft.

[0051] In particular, the threaded spindle or adjusting screw can be hollow, i.e., it can have an open passage for the locking screw extending from the first longitudinal end or end face of the threaded spindle to the second longitudinal end or end face of the threaded spindle.

[0052] The thread of the axle receptacle is preferably designed as an internal thread for interaction with an external thread of the locking screw. The locking screw can extend through the bore in the threaded spindle along the adjustment direction and interact with the internal thread of the axle receptacle; that is, the locking screw can be screwed into the receptacle in the axle of the roller. The receptacle in the axle can be arranged coaxially with the threaded bore in the support and with the bore in the threaded spindle and extend in the adjustment direction.

[0053] One end of the threaded spindle can be held pressed against the axis by the locking screw to lock the threaded spindle in the end position.

[0054] In this design, the locking element, in particular the locking screw, can be actuated from the same side of the support as the threaded spindle. This facilitates assembly and disassembly. The threaded spindle can be actuated to adjust the position of the roller's axle, i.e., it can be inserted and screwed in. The locking element, or locking screw, can be inserted and screwed in from the same side of the support as the threaded spindle itself, thus locking the roller in its intended, operational end position.

[0055] The counter element can be designed as a locking screw with a head to lock the threaded spindle in the end position.

[0056] The locking screw can be positioned with its head against the support or against the second end of the threaded spindle, the end facing away from the roller axis. This secures or fixes the desired position of the threaded spindle between the roller axis and the head of the locking screw, or the position of the roller axis relative to the support.

[0057] An advantageous embodiment of the invention is characterized in that the curved rail is designed as a hollow profile rail and has at least two internal profile contours, each of which forms an inner and outer running track with respect to the radius of curvature and which engages with a complementary profile contour of the running rollers.

[0058] The profile contours are advantageously designed to ensure a positive engagement of the roller bodies of the guide rollers in the running tracks of the curved rail. This preferably ensures that the guide rollers, or rather the roller bodies of the guide rollers, are axially fixed. This prevents axial play, which contributes to low-friction running of the support. Advantageously, the profile contours are approximately prismatic.

[0059] For example, the rollers can include at least one roller body designed with a prismatic contour in the manner of a diabolo roller.

[0060] One of these diabolo rollers within the meaning of the present invention is understood to be a constricted roller which encompasses a profile contour or running track on both sides, so that the roller body is axially fixed with respect to the axis supported on it.

[0061] The rollers or roller bodies of the rollers can have a simple rectangular groove that interacts with a rectangular profile of the respective track. However, it is advantageous if the tracks include inclined guide surfaces that interact with corresponding inclined running surfaces of the roller body, so that the contact area between the roller body and the track can be minimized via the angle of the guide surfaces, which contributes to reduced rolling friction.

[0062] In some versions, the curved track has a C-shaped cross-section. The curved track can have inclined wall sections in cross-section, i.e., sections running at an angle to the axes of the rollers, and / or sections running parallel to the axes of the rollers, or it can have inclined and / or parallel guide surfaces. The shape of the roller bodies can be adapted to the cross-sectional shape of the curved track. Each roller can have a convex roller body comprising conical and / or cylindrical sections. Thus, the roller body can have running surfaces that are inclined and / or parallel to the axis of the roller. The respective roller can roll along the inclined wall sections of the curved track with the conical sections of its roller body.

[0063] In a preferred embodiment of the system according to the invention, the rollers each comprise roller bodies made of thermoplastic material. Such rollers can run relatively quietly. These can, for example, be injection-molded from a thermoplastic material, such as a polyamide, particularly preferably from PA6.

[0064] Preferably, the thermoplastic material of the roller body comprises a tribologically optimized plastic. In this context, this refers to a polymeric material that has a low coefficient of friction with the track. This includes, in particular, the thermoplastics polyethylene, polypropylene, polyacetal, polycarbonate, polyamide, polyvinyl chloride, polytetrafluoroethylene, and, among thermosets, phenolic resins. To further reduce friction, these plastics can contain lubricants, especially finely divided solid lubricants such as molybdenum disulfide or graphite. Such lubricant-containing polymers are also referred to as tribopolymers.

[0065] In a preferred and advantageous embodiment according to the invention, the rollers are each mounted on ball bearings. The rollers can, for example, each be mounted on a shaft that is attached to or fixed to the support via deep groove ball bearings designed as industrial bearings, in particular via radial bearings.

[0066] The curved rail can be designed as an extruded profile, preferably as an aluminum extrusion profile. The invention is explained below with reference to and based on an exemplary embodiment illustrated in the accompanying drawings.

[0067] They show:

[0068] Figure 1: a schematic representation of an embodiment of the system according to the invention, in which only a partial circular arc of the guide rail is shown;

[0069] Figure 2: in a schematic representation of principle, a sectional view along the line EE in Figure 1;

[0070] Figure 3: a schematic representation of principle, showing a perspective front view of an embodiment of the system according to the invention;

[0071] Figure 4: in a schematic representation of principle, a sectional view along the lines AA in Figure 3;

[0072] Figure 5: in a schematic principle representation, a sectional view corresponding to Figure 2 along lines BB in Figure 4;

[0073] Figure 6: in a schematic principle representation, a perspective view of the support with the rollers arranged on it, without the curved track of the system;

[0074] Figure 7: a schematic representation of principle corresponding to the sectional view according to Figure 4, wherein below each of the cut rollers shown in Figure 7 a corresponding cross-section through the system is shown;

[0075] Figure 8A, 8B: a partial view of another embodiment of the system in cross-section.

[0076] The system shown in Figure 1 comprises a curved track 1, which is designed as a hollow profile and forms an inner guide profile for three rollers 2, 3 of a support 4 that can be displaced along the curved track 1 on a circular path. The support 4 is designed to receive an object (not shown) and may, for example, have fastening means (not shown) for this purpose. The curved track 1 has a constant radius of curvature.

[0077] Figure 1 shows only a section of the curved track 1. The curved track 1 can extend over a complete circular arc or over any angular segment of a circular arc. In the preferred embodiment of the system according to the invention, the curved track 1 is designed as an aluminum extrusion profile and comprises two opposing, conical profile webs 5 circumferentially arranged inside the profile, each forming a track for the rollers 2, 3, with an outer and an inner track being provided relative to the radius of curvature of the curved track 1.

[0078] As can be seen in particular from Figure 2, the rollers 2, 3 have a prismatic, circumferential constriction corresponding to the cross-section of the profile webs 5, with running surfaces 6 whose angle of repose corresponds approximately to the angle of the conical guide surfaces 7 of the profile webs 5. The running surfaces 6 of the rollers 2, 3 alternately bear against the guide surfaces 7 of the profile webs 5 on the inside and outside with respect to the radius of curvature of the curved track 1, whereby the running surfaces 6 of the rollers 2, 3 encompass the profile webs 5, so that the support 4 is fixed in a direction transverse to its displacement direction or guiding direction on the circular path defined by the curved track 1.

[0079] The rollers 2, 3 are each mounted on axles 8, the axles 8 extending through a circular arc-shaped slot 9 in one side of the curved track 1 and being fixed to the support 4 in a rotationally fixed manner. The rollers 2, 3 each comprise a roller body which is rotatably mounted on the axles 8 by means of ball bearings 10. The support 4 is thus displaceable along the circular path defined by the curved track 1.

[0080] As can be seen particularly in Figure 6, the axles 8 of the rollers 2, 3 are arranged transversely to the longitudinal extent of the support 4. This axle offset ensures, on the one hand, that the rollers 2, 3 can follow the circular path defined by the curved track 1, and on the other hand, that each roller 2, 3 bears load only on one side, i.e., is supported on one side against a single profile web 5 of the guide rail. In this way, the rollers 2, 3 roll smoothly on the tracks formed by the curved track 1 without slippage, so that only rolling friction occurs between the rollers 2, 3 and the profile webs. Furthermore, the bearing clearance of the roller bearing supported by the rollers 2, 3 can be adjusted via the axle offset. Finally, it is also possible for a single support 4 to be adjustable on curved tracks 1 with different radii of curvature.

[0081] The support 4 comprises exactly three rollers 2, 3, with two first rollers 2 being provided which, depending on the direction of displacement of the support 4 on the circular path defined by the curved track 1, are either leading or lagging. A second, middle roller 3 is adjustable transversely to the longitudinal extent of the support 4 or transversely to the direction of displacement of the support 4 on the curved track 1, so that the axial offset of the rollers 2, 3 is adjustable, as will be described in detail below.

[0082] As can be seen in particular from the illustration in Figure 6, the axis 8 of the second roller 3 passes through an elongated hole 11 on the side facing the support 4 in the installed position on the curved track 1.

[0083] The axis 8 of the second roller 3 can be manually adjusted radially by means of a threaded spindle 12, which extends in a threaded bore 13 of the carrier 4 (see Figure 2), using a tool (not shown). In the embodiment shown in Figure 2, the threaded spindle 12 is provided on one side with a spindle head 14, which has a tool engagement 15, for the purpose of adjustment with a tool. On the side of the threaded spindle 12 opposite the spindle head 14, it includes an adjusting thread 16, which engages in the threaded bore 13 of the carrier 4 and forms a mechanical actuating drive or spindle drive 100 with the adjusting thread 16 within the threaded bore 13.

[0084] The shaft 18 of the threaded spindle 12 passes through a bearing bore 19 of the axis 8, wherein a circumferential shoulder 20 is provided within the bearing bore 19, which engages in a circumferential groove 21 in the shaft 18 of the threaded spindle 12, so that a displacement of the threaded spindle 12 causes a corresponding movement and radial adjustment of the axis 8 of the second roller 3. In this embodiment, a setscrew 22 is provided as a locking element. This allows the threaded spindle 12 to be radially fixed or locked after setting a desired axis offset or feed path.

[0085] The term radial, as used in connection with the present description, basically refers to the radius of curvature of the curved rail 1.

[0086] Figure 7 illustrates the position of the rollers 2, 3 within the curved track 1 and their engagement with the profile webs 5 of the curved track 1. The sectional view according to Figure 7a) shows the first roller 2 in cross-section in the arrangement shown above. The roller 2 is in engagement with the radially outer profile web 5.

[0087] Figure 7b) shows the second roller 3 or middle roller 3, which is in engagement with the radially inner profile web 5 of the guide profile.

[0088] Figure 7c) shows the further second roller 2, which in turn is in engagement with the radially outer profile web 5 of the curved track 1.

[0089] Figures 8A and 8B show a different embodiment of the system according to Figure 1, which differs from the embodiment in FIGS. 2 to 7 by the shape of the rollers, the guide profile of the cam rail, and by the shape of the spindle drive.

[0090] The curved track 81, shown in cross-section in FIGS. 8A, 8B, has an inner C-shaped profile with two opposing running tracks – an inner running track 17a with respect to the radius of curvature of the curved track, and an outer running track 17b with straight guide surfaces 87, which are partly inclined to the axis 88 and partly parallel to the axis 88. The rollers in this embodiment have roller bodies with a convex surface and with conical and cylindrical running surfaces 86, with which the rollers roll on the guide surfaces 87 of the curved track 81. The roller body is mirror-symmetrical with respect to a plane that is perpendicular to the axis 88 of the roller 83.

[0091] Shown in Figs. 8A, 8B is one of the second running rollers 83. It is mounted on an adjustable axle 88 via ball bearings 10 on the support 4. The axle 88 is adjustable transversely to the displacement direction of the support 4 on the curved track 81, so that the axle offset between the first running rollers and the second running roller 83 shown is adjustable, i.e., adaptable to the radius of curvature of the curved track 81.

[0092] In this embodiment, the spindle drive 800 for adjusting the axis 88 of the second roller 83 comprises a hollow threaded spindle 812 with an external thread, which is the feed thread 816 of the spindle drive 800. The threaded spindle 812 can thus be manually screwed into a threaded bore 813 of the support 4, extending perpendicular to the displacement direction of the support in the adjustment direction, using a tool (not shown). This causes a first end face of the threaded spindle 812 to engage with the axis 88 of the second roller 83, so that, as the screwing continues, the axis 88 is moved along the adjustment direction, i.e., radially with respect to the radius of curvature of the cam track 81, to an end position. In the end position of the axle 88, the second roller 83 is in contact with the track opposite the track with which the first rollers are in contact.Either in the end position the first rollers are in contact with the inner track 17a and the second, adjustable roller is in contact with the outer track 17b, as shown in the example in FIG. 4 or 7, or vice versa.

[0093] In the embodiment shown in FIGS. 8A, 8B, a locking screw 822 with a head is used as a counter element for locking the threaded spindle 812. The threaded spindle 812 has a through-hole 824 extending from the first end face of the threaded spindle 812 to its second end face for receiving the locking screw 822. The axis 88 of the second roller 83 has a receptacle 823 extending in the adjustment direction with an internal thread, which, in the intended operating position or in the intended ready-for-operation state (as shown in FIGS. 8A, 8B), is arranged coaxially to the threaded bore 813 of the support 4 and coaxially to the through-hole 824 of the threaded spindle 812.The locking screw 822, in its intended operating position, extends through the through-hole 824 of the threaded spindle 812 and is screwed into the receptacle 823 of the axis 88 until the head of the locking screw 822 comes to rest against the second end face of the threaded spindle 812. This allows the threaded spindle 812 to be radially fixed or locked after setting a desired axis offset or feed path. Ma 5. November 2025.

[0094] Applicant: igus GmbH

[0095] 51147 Cologne

[0096] Roller bearing assembly with curved rail

[0097] Reference symbol list

[0098] 1 Curved rail

[0099] 2 first rollers

[0100] 3 second roller

[0101] 4 carriers

[0102] 5 profile ribs

[0103] 6 running surfaces

[0104] 7 guide surfaces

[0105] 8 axes

[0106] 9 slots

[0107] 10 ball bearings

[0108] 11 elongated hole

[0109] 12 threaded spindle

[0110] 13 threaded holes

[0111] 14 Spindle head

[0112] 15 Tool intervention

[0113] 16 feed threads

[0114] 17a inner lane;

[0115] 17b outer running track

[0116] 18 shaft

[0117] 19 bearing bore

[0118] 20b paragraph

[0119] 21 Federal Government

[0120] 22 Grub screw 81 Curved rail

[0121] 83 second roller

[0122] 86 running surfaces

[0123] 87 guide surfaces 88 axes

[0124] 100 spindle drive

[0125] 800 spindle drive

[0126] 812 Threaded spindle

[0127] 813 Threaded hole 816 Feed thread

[0128] 822 Locking screw

[0129] 823 Mounting bracket with internal thread in the axis

[0130] 824 Feedthrough in threaded spindle

Claims

May 5, 2025 Applicant: igus GmbH, 51147 Cologne Roller bearing assembly with curved rail Claims 1. System for guiding at least one object at least on a part of a circular path or around an axis of rotation, comprising at least one curved track (1) with at least one guide profile, which has at least two inner and outer running tracks (17a) extending at least over a partial circular arc and with respect to a radius of curvature of the curved track (1).17b) comprising at least one support (4) displaceable along the curved track (1), in particular for receiving or fastening the at least one object, wherein the support (4) is mounted on a plurality of rollers, wherein at least three rollers (2,3), preferably exactly three rollers (2,3), are arranged one behind the other in the displacement direction of the support (4), and at least one first roller (2) is arranged transversely to the displacement direction along the circular path with respect to at least one second roller (3), such that the rollers (2,3) are engaged either with the inner track (17a) or with the outer track (17b) of the guide profile with respect to the radius of curvature of the curved track (1).

2. System according to claim 1, characterized in that the radius of curvature of the curved track (1) over a total guide length of the curved track (1) has such a profile that the rollers (2, 3) are in continuous contact with the curved track (1) during a displacement over the total guide length or have a constant clearance to the curved track (1), wherein in particular the displacement direction and thus the curved track (1) has a constant radius of curvature over the total guide length or changes exclusively in a range adapted to an adjustability of the rollers (2, 3) relative to each other and / or the displacement direction is curved in a single plane.

3. System according to one of the preceding claims, characterized in that at least one roller (2, 3) is oriented in the displacement direction of the carrier and / or at an angle to the The displacement direction of the support, which is greater than 0°, is adjustable.

4. System according to one of the preceding claims, characterized in that at least one roller (3) is adjustably arranged transversely to the displacement direction of the support (4) on the support (4).

5. System according to one of claims 3 or 4, characterized in that at least one actuator is provided for adjusting the at least one roller, with which an axial offset of the rollers (2,3) transverse to the displacement direction of the support (4) can be adjusted.

6. System according to one of the preceding claims, characterized in that the rollers (2, 3) with respect to the displacement direction of the carrier (4) comprise at least two first rollers (2) and at least one second roller (3) arranged between the first rollers (2), wherein the at least two first rollers (2) comprise a leading and a trailing roller.

7. System according to claim 6, characterized in that the second roller (3) has an axis (8) adjustable transversely to the direction of displacement or radially via a feed path, via which the axis offset of the rollers (2,3) can be adjusted.

8. System according to one of claims 1 to 7, characterized in that the radius of curvature of the curved rail (1) is greater than or equal to 300 mm up to and including 4000 mm.

9. System according to one of claims 6 to 8, characterized in that The adjustable axis offset is greater than or equal to 0.2% up to and including 5% of the radius of curvature.

10. System according to one of claims 6 to 9, characterized in that the axis offset is determined as a function of the radius of curvature and as a function of a pitch dimension between the first running rollers (2), wherein in particular the system comprises several curved rails (1) which differ in their radii of curvature and which are each designed corresponding to the support (4), wherein, to realize a first operating state of the system, the support (4) can be arranged displaceably along a first of the curved rails (1) and, to realize a second operating state of the system, the support (4) can be arranged displaceably along a second of the curved rails (1), wherein the first curved rail (1) has a larger radius of curvature than the second curved rail (1) and the axis offset in the first operating state is smaller than in the second operating state.

11. System according to one of claims 6 to 10, characterized in that the first rollers (2) are spaced apart from each other with a pitch of greater than or equal to 70 mm to less than or equal to 120 mm.

12. System according to one of claims 1 to 11, characterized in that an axis (8; 88) of at least one roller (2,3) is adjustable in such a way as to be mounted, in particular in an elongated hole (11) of the support (4), and that a spindle drive (100; 800) is provided for adjusting the axis (8; 88) of the roller, which comprises a threaded spindle (12; 82) acting on the axis (8; 88).

13. System according to claim 12, characterized in that the threaded spindle (82) is aligned with the axis with one end face (88) acts to move the axis (88) along the To shift the adjustment direction.

14. System according to claim 12 or 13, characterized in that the spindle drive (100; 800) includes means for locking the threaded spindle (12; 82) in an end position, wherein in particular the means include a counter element, in particular are designed as a counter element.

15. System according to claim 14, characterized in that the counter element is designed as a screw with a screw thread, wherein the axis (8; 88) or the support (4) has a receptacle facing the threaded spindle (12; 82) with a thread corresponding to the screw thread, wherein, for locking the threaded spindle (12; 82) in the end position, the screw can be screwed into the corresponding thread in such a way that it exerts a clamping force against the threaded spindle (12; 82).

16. System according to claim 15, characterized in that the counter element is a locking screw (822) and the threaded spindle (82) is a through-hole (824) open towards receiving (823) the axis (88) for the locking screw (822) has, in particular the thread of the receptacle (823) is designed as an internal thread and, to lock the threaded spindle (82) in the end position, a front end of the threaded spindle is held pressed against the axis (88) by the locking screw (822).

17. System according to one of claims 14 to 16, characterized in that the counter element and the threaded spindle (82) are of the same They can be operated from the side of the carrier.

18. System according to one of claims 1 to 17, characterized in that the curved rail (1) is designed as a hollow profile rail and has at least two internal profile contours, in particular prismatic profile contours, which each form an inner running track (17a) and an outer running track (17b) with respect to the radius of curvature and which engages with a complementary contour of the running rollers (2,3).

19. System according to claim 18, characterized in that the rollers (2,3) comprise at least one roller body which is designed in the manner of a diabolo roller with a prismatic contour.

20. System according to one of claims 1 to 19, characterized in that the rollers (2, 3) each comprise roller bodies made of thermoplastic material, in particular wherein the thermoplastic material of the roller bodies comprises a tribologically optimized material, preferably in the form of a tribopolymer.

21. System according to one of claims 1 to 20, characterized in that the rollers (2,3) are supported by a rolling bearing, in particular a ball bearing.

22. System according to one of claims 1 to 21, characterized in that the curved rail (1) is designed as an extruded profile, preferably as an aluminum extrusion profile.

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