Sliding bearing and sliding bearing guide

Abstract

The invention relates to a sliding bearing for guiding on a guide rail, which is preferably designed as a curve guide. The sliding bearing has at least one slide with a bearing plate, comprising at least three bearing receiving areas which are provided on the bearing plate and in which a respective slide element with a continuous slide opening is arranged. The slide opening has a cross-sectional contour which is designed to complement a guide section of the guide rail and which surrounds the guide section preferably in a form-fitting manner, and the slide elements are designed to be calotte-shaped and are mounted in a respective spherical receiving opening of the bearing receiving areas. At least some of the bearing receiving areas, in particular all of the bearing receiving areas, are designed in multiple parts and are made of respective first and second calotte shell sub-contours, which complement a spherical contour, for receiving a slide element.

Description

[0001]Ma / mb March 26, 2024 Applicant: igus GmbH 51147 Cologne Plain bearing and plain bearing guide The invention relates to a plain bearing for guidance on a guide rail, preferably designed as a curved guide, wherein the plain bearing comprises at least one carriage with a bearing plate, with a plurality of bearing receptacles provided on the bearing plate, in each of which a sliding element with a continuous sliding opening is arranged, wherein the sliding opening has a cross-sectional contour complementary to a guide section of the guide rail, preferably encompassing the guide section in a form-fitting manner, the sliding elements are designed in the shape of a spherical cap and are each mounted in a spherical receiving opening of the bearing receptacles. The invention further relates to a plain bearing guide comprising at least one elongated guide rail, which is designed as a curved rail, which is curved in at least one plane,and at least further comprising a plain bearing of the type described above. Plain bearings and plain bearing guides of the type mentioned above, also referred to as generic, are known in the prior art as so-called linear sliding guides. A plain bearing and a plain bearing guide of the type mentioned above are known, for example, from DE 202016 101 698 U1. DE 202016 101 698 U1, which is considered generic prior art, describes a plain bearing for guidance on a double guide rail with two guide profiles or guide sections, which has a carriage with four bearing receptacles, each of which accommodates spherical cap-shaped sliding elements. The bearing receptacles are arranged in two parallel, spaced-apart pairs opposite one another.To ensure the carriage's ability to navigate curves, to compensate for different radii on different guide rails, and in particular to compensate for gauge tolerances between the parallel guide sections of the guide rails, it is provided that those bearing receptacles arranged on a first side for guidance on one guide profile are designed as floating bearings that can be displaced transversely to the running direction, and the two bearing receptacles arranged on the opposite side for guidance on the other guide profile are designed as fixed bearings that are stationary with respect to the carriage. For this purpose, it is provided that the bearing receptacles designed as floating bearings are displaceably mounted in transverse grooves extending perpendicular to the running direction. The carriage is made of an extruded aluminum profile into which corresponding transverse grooves are machined. The plain bearings,The sliding elements, which encompass the guide sections of the guide rails, are manufactured as spherical cap-shaped sliding elements made of an injection-moldable plastic and inserted into the correspondingly spherically shaped bearing receptacles. The sliding elements, made of an engineering plastic, are designed and dimensioned in such a way that they can be inserted into and removed from the respective receiving openings of the bearing receptacles. Although the sliding bearing according to DE 202016 101 698 U1 is particularly suitable and advantageous with regard to its functionality and in particular for guiding curved rails, especially with a multiply curved rail path, it is relatively complex to manufacture. Further prior art is known, for example, from the publications EP 1379 791 B1 and DE 202021 105 330 U1. The invention is based on the object of providing a sliding bearing and a sliding bearing guide of the type mentioned above.which are particularly simple and cost-effective to manufacture. In particular, the design of the plain bearing and the plain bearing guide is to be improved to the extent that the simplest and almost complete production from an engineering plastic, in particular from a thermoplastic, injection-moldable plastic, is possible. The object is achieved by providing a plain bearing with the features of claim 1 and by providing a plain bearing guide with the features of claim 8. Advantageous embodiments of the invention emerge from the subclaims. According to a first aspect of the invention, a plain bearing is provided for guidance on a guide rail, preferably designed as a curved guide, wherein the plain bearing comprises at least one carriage with a bearing plate, with a plurality of bearing receptacles provided on the bearing plate,in each of which a sliding element with a continuous sliding opening is arranged, wherein the sliding opening has a cross-sectional contour complementary to a guide section of the guide rail, preferably encompassing the at least one guide section in a form-fitting manner, the sliding elements are designed like spherical caps and are each mounted in a spherical receiving opening of the bearing receptacles, wherein the sliding bearing according to the invention is characterized in particular in that at least some of the bearing receptacles, in particular a majority of the bearing receptacles, in particular all of the bearing receptacles, are each designed in several parts and are each formed by first and second spherical shell partial contours complementing each other to form a spherical contour for receiving a sliding element. The sliding bearing is designed in particular toto ensure safe and easy guidance on a double rail with two guide sections / guide profiles extending parallel to one another. The guide rail is preferably designed as an extruded aluminum profile with two cranked areas or longitudinal sides that form the guide sections. Due to the cranked design, the guide sections are each connected to a central area of ​​the guide rail via a web. Generally speaking, the guide rail preferably extends elongatedly in the running direction of the carriage, along which the carriage is guided relative to the guide rail and can be displaced thereon. The running direction is a direction predetermined by the shape of the guide rail. Preferably, the running direction has a curvature whose radius of curvature is a multiple, in particular at least five times,in particular, at least ten times the length of the guide rail in the running direction. Generally, the guide sections are each preferably designed in the manner of a cylinder with its cylinder axis extending in the running direction. When a curved running direction is provided, the guide sections are preferably designed as cylinders with their cylinder axis curved following the running direction, so that their cylinder axes are curved and run parallel to the running direction, with their cross sections running perpendicular to the running direction remaining at least substantially constant along their extension along the running direction. Generally, the guide rail has an at least substantially constant cross section overall over its extension in the running direction. The carriage preferably has a cross-sectional profile corresponding to the guide rail.so that the carriage can be guided in the running direction on the guide rail in such a way that it is fixed to the guide rail perpendicular to the running direction and is only movable in the longitudinal direction relative to the guide rail. According to the invention, the sliding elements are designed in the manner of a spherical cap. Thus, the sliding elements form a section of a spherical shape with their outer side, so that they have a spherical outer side with which they can be arranged in the spherical receiving opening of their respective associated bearing receptacles. The sliding elements and the bearing receptacles each form at least a section of a spherical shape, so that the sliding elements can be translationally fixed and rotatably held by the bearing receptacles. In particular, the multi-part design of the bearing receptacles has the advantage that the plain bearing, apart from fastening elements for fastening parts of the bearing receptacles,can be manufactured much more easily entirely from thermoplastic material, in particular by means of relatively simple injection molding tools that do not require sliders and cores, as are required for complex one-piece contours with undercuts. This significantly simplifies the manufacturability of the plain bearing according to the invention. In a particularly advantageous embodiment of the plain bearing according to the invention, it is provided that said at least some of the bearing receptacles, in particular the bearing receptacles, are formed from a thermoplastic material, so that the partial contours of the bearing receptacles are formed from a thermoplastic material. In an advantageous embodiment, the bearing plate is formed from a thermoplastic material,wherein generally preferably the bearing plate integrally forms the first partial contours of said bearing receptacles. In one embodiment, the carriage is preferably formed entirely from a particularly thermoplastic plastic. Generally preferably, the first spherical shell partial contours are formed integrally with the bearing plate of the carriage. The carriage can be formed as an injection-molded component from a filled thermoplastic plastic, preferably from a fiber-reinforced, in particular a glass-fiber-reinforced plastic, which imparts particular strength to the carriage as a load-bearing part of the sliding guide or the sliding bearing. The carriage can be provided with fastening means for fastening at least one component to be guided. In one embodiment, by a fixed positional fixation of the bearing receptacles of the carriage relative to one another on a guide of the bearing receptacles that can be displaced transversely to the running direction,This means that there is no division into floating bearings and fixed bearings, as was previously provided for in the prior art. The described design of the bearing receptacles or the slide made of thermoplastic material has proven to be particularly advantageous. The slide, including the bearing receptacles, can be manufactured from a total of two or three separate plastic parts due to the multi-part design of the bearing receptacles, for example, which can be produced in a single, relatively simple injection mold. The plastic parts can be formed, for example, by the bearing plate and the holding blocks explained below. Preferably, all of the plastic parts are fixed in position relative to one another while forming the slide. Preferably, the bearing receptacles are fixed in position relative to one another as a result. Preferably, the centers of the sliding elements held in the bearing receptacles are fixed in position relative to one another as a result.so that the sliding elements are rotatably mounted in the bearing receptacles, but are fixed in position. Suitable fixing means, such as screws, can be used to secure the plastic parts to one another. The screws can be made of plastic or metal, for example. The sliding elements inserted into the bearing receptacles can also be made of an injection-molded thermoplastic. The sliding elements can be designed, for example, as spherical cap-like sliding elements with a spherical outer surface, preferably symmetrical about a sliding axis around which they are rotatably mounted.which are mounted in a correspondingly designed spherical receiving opening of the bearing receptacles in a ball-and-socket manner. The sliding elements are expediently arranged in the bearing receptacles so as to be rotatable about several sliding axes. The sliding elements are also preferably made of plastic by injection molding and can, for example, be designed as a partial ring or partial spherical ring with a spherical outer surface. The sliding opening of the sliding elements can, for example, have a polygonal, preferably rectangular or square cross-section, and interact with a corresponding rectangular or square cross-section of one or more guide sections of the guide rail. The sliding elements preferably each have a recess through which their outer side or outer surface is connected to the sliding opening.so that the described web of the slide can extend through this recess. Thus, the sliding elements are preferably designed as a slotted spherical cap, wherein the recess forms the slot. Preferably, the slot is dimensioned and the sliding elements are designed to be elastic such that the sliding elements can each be inserted into their respective associated bearing receptacle by compression. This has the particular advantage that the slide can initially be manufactured without the sliding elements, wherein, in particular, as explained, its plastic parts are connected to one another in a fixed position, after which the sliding elements can be inserted into the bearing receptacles. As a sliding material for the sliding elements but also for the spherical shell partial contour in the bearing receptacles, in particular as the above-mentioned thermoplastic material,A sliding plastic is advantageously used. In this case, this refers to a polymeric material that has a lower coefficient of friction with the surface of the guide section than the material of the slide body. In particular, these include thermoplastic polymers such as polyethylene, polypropylene, polyacetal, polycarbonate, polyamide, polyvinyl chloride, polytetrafluoroethylene, and thermosetting phenolic resins. To further reduce friction, these plastics can be filled with lubricants, in particular fine-particle solid lubricants such as molybdenum disulfide or graphite. Such lubricant-containing polymers are also referred to as tribopolymers. In an expedient and advantageous embodiment of the plain bearing according to the invention, it can be provided that at least one bearing receptacle, preferably two bearing receptacles,are each formed by a first spherical shell partial contour of the bearing plate and at least one second complementary spherical shell partial contour of a retaining block that is attached to the bearing plate. The retaining block can be designed as a separate injection-molded plastic component. Thus, the retaining block or retaining blocks and the bearing plate can be designed as independently manufactured parts, in particular plastic parts. The retaining block is preferably fixed in position to the bearing plate. In one embodiment, the retaining block and bearing plate have mutually corresponding fastening devices, for example, locking devices. In one embodiment, fastening means are provided by means of which the retaining block is connected to the bearing plate in a fixed position. It has proven particularly advantageous to provide mutually corresponding engagement devices on the retaining block and on the bearing plate in such a way thatthat the holding block and bearing plate are fixed in their position relative to one another by the interlocking of their engagement devices with respect to two spatial directions, so that the engagement devices form a positive connection with respect to two spatial directions. Preferably, the engagement devices are pressed into one another in a press fit, so that a force connection is ensured in the third spatial direction by the engagement devices. For example, a first of the engagement devices can be designed as a mandrel, a second of the engagement devices as a receptacle corresponding to the mandrel, wherein one of the first and second engagement devices is provided on the holding block and the other on the bearing plate. Particularly preferably, fastening means are provided, for example screws,which prevent relative movement of the holding block relative to the bearing plate in the third spatial direction. Generally preferred fastening means for fixing the holding block to the bearing plate are, for example, threaded bolts and nuts, wherein the nuts can engage positively in polygonal recesses of the holding block or the bearing plate as an anti-twist device. The bearing plate can accommodate metal guide bushings inserted into through-holes, which can absorb the preload force introduced into the slide by the fastening means. The holding block is preferably formed in one piece from a thermoplastic material. The holding block can also be formed, for example, from a filled or fiber-reinforced thermoplastic material. In a particularly advantageous embodiment of the invention, it is provided that the holding block has at least two spaced-apart spherical shell partial contours,which are formed as an integral component of the holding block. The spherical shell partial contours of the holding block and the corresponding spherical shell partial contour of the bearing plate complement each other to form the bearing receptacles when the holding block is attached to the bearing plate of the slide. In an advantageous variant of the plain bearing according to the invention, at least two holding blocks are provided, extending in a running direction of the slide, each forming a plurality of spherical shell partial contours of the plain bearing spaced apart in the running direction and, in particular, being formed as a single piece. Such a plain bearing advantageously comprises a slide formed from a single bearing plate and two holding blocks, wherein each holding block forms two bearing receptacles with the bearing plate on a longitudinal side of the slide, each of which encloses sliding elements. The bearing receptacles, which a first of the holding blocks forms together with the bearing plate,are thus spaced apart from each other perpendicularly to the longitudinal direction by the bearing receptacles formed by a second of the holding blocks together with the bearing plate. Preferably, a specific one of the holding blocks, together with the bearing plate, forms several bearing receptacles, wherein these bearing receptacles are spaced apart from each other in the running direction. The sliding elements can be arranged such that two sliding elements arranged one behind the other at a distance in the running direction of the carriage each engage around a guide section of the guide rail. By appropriately dimensioning the sliding openings passing through the sliding elements and due to the fact that the sliding elements are each pivotably mounted in the bearing receptacles, the curveability of the sliding bearing is ensured in at least one plane that extends essentially perpendicular to the running direction and is spanned by the axes X, Y of a Cartesian coordinate system.in which or parallel to which the running direction extends. This bend or curvature is referred to below as a Y-bend, whereby the running direction of the plain bearing includes a component in the X-direction, the curvature of the guide rail has a component in the Y-direction, i.e., vertical, and the guide sections of the guide rail, which is preferably designed as a double rail, are spaced apart from one another in the Z-direction. Accordingly, for example, the holding blocks are spaced apart from one another in the Z-direction, whereas they extend in the X-direction on the carriage. Due to the shape of the outer surface of the sliding elements, no additional joints, bearings, or moving parts are required to implement a pivotal mounting of the sliding elements and thus to ensure the curveability of the plain bearing. In an expedient and preferred variant of the plain bearing according to the invention, the carriage has four bearing receptacles,which are arranged in two opposite pairs spaced apart in the running direction, wherein all bearing receptacles are stationary with respect to the bearing plate of the carriage. Preferably, each bearing receptacle of each such pair is formed by a different retaining block, wherein the respective retaining block forms a second partial contour and the bearing plate forms a first partial contour of the respective bearing receptacle. In particular, by omitting one or more loose bearings, a significant structural simplification of the plain bearing according to the invention is achieved. A further aspect of the invention relates to a plain bearing guide comprising an elongated guide rail, which is designed as a curved rail, which extends curved in at least one plane and comprises at least one plain bearing with the features described above. The curved rail according to the invention is preferably curved only in a single plane,i.e., it has a simply curved profile. Nevertheless, the plain bearing guide can, in principle, also comprise a curved rail with a curved profile along several spatial axes. The curved rail can have at least one curvature in a vertical direction, which extends substantially perpendicular to the running direction (Y-bend) and which is spanned by the axes X, Y, in which or parallel to which the running direction extends. As already mentioned, the curved rail can be designed as a double rail with at least two guide sections extending parallel and spaced apart in the running direction, which are each encompassed by two sliding elements of the carriage arranged one behind the other at a distance in the running direction. The guide sections can each have a polygonal profile, which is complementary to a corresponding cross-sectional profile of the sliding openings. The person skilled in the art will recognize,that the design of the cross-sectional profiles is not critical to the invention; rather, other cross-sectional profiles that complement each other can also be selected. Furthermore, it should be noted at this point that a plain bearing according to the invention can have features in embodiments,which are explained here in connection with generic plain bearings. The invention is explained below with reference to and with reference to an exemplary embodiment shown in the accompanying drawings. They show: Figure 1 shows a schematic, basic illustration of a perspective view of an embodiment of a plain bearing guide according to the invention; Figure 2 shows a schematic, basic illustration of an exploded view of an embodiment of a plain bearing according to the invention; Figure 3 shows a schematic, basic illustration of a perspective view of an embodiment of a plain bearing according to the invention. The plain bearing guide 10 according to the invention comprises a guide rail 20 designed as a curved rail and a plain bearing 30,which is designed as a linear plain bearing and is slidably displaceable along the guide rail 20 in the longitudinal direction of the guide rail 20. The longitudinal direction corresponds to the explained running direction of the carriage. The guide rail 20 is designed as a double rail and consists of an extruded aluminum profile that extends in the longitudinal direction of the guide rail 20 and has two guide profiles designed as guide sections 21, rectangular in cross-section. The guide rail 20 comprises a rail body 22 with an approximately C-shaped cross-section, on which the guide sections 21 are formed, which are designed as cranked edges of the rail body 22 that extend laterally in the running direction. Accordingly, the guide sections 21 are each designed as a curved cylinder and are connected to a central region of the rail body (22) via a web. The guide rail 20 is curved in one plane,which is spanned by an X-axis and a Y-axis of a coordinate system shown in Figure 1. The sliding bearing 30, which is slidably mounted on the guide rail 20, is guided in the described embodiment on a curved path extending in the XY plane. The sliding bearing 30, which will be discussed in more detail below with reference to Figures 2 and 3, is essentially designed as a multi-part, injection-molded component made of thermoplastic material. As can be seen particularly from the exploded view in Figure 2, the sliding bearing 30 comprises a carriage 31, which is composed of a bearing plate 32 made of injection-molded thermoplastic material and two holding blocks 33 and fastening means connecting them.The bearing plate 32 and the holding blocks 33 are each made of thermoplastic material. The holding blocks 33 are fastened to the bearing plate 32 by means of threaded bolts and corresponding nuts 34 (not shown in the drawing). As an alternative to such a fastening with bolts and nuts 34 as fastening means, a locking of the holding blocks 33 to the bearing plate 32 can also be provided. The locking can be designed as a releasable or permanent locking. The holding blocks 33 are designed as elongated, strip-shaped elements extending in the running direction of the plain bearing 30 or the carriage 31. As can be seen in particular from Figure 1, the running direction includes a movement component in the X direction and, naturally, also a movement component in the Y direction of the coordinate system shown in Figure 1. The bearing plate 32 and the holding blocks 33 form bearing receptacles 37,which enclose spherical cap-like sliding elements 35 made of thermoplastic material. To guide the sliding elements 35, both the bearing plate 32 and the retaining blocks 33 form spherical shell partial contours 36 complementary to the outer contour of the sliding elements 35, in which the sliding elements 35 are mounted for sliding and rotation. Each spherical shell partial contour 36 in the bearing plate 32 and a spherical shell partial contour 36 in a retaining block 33 form a bearing receptacle 37 in which a sliding element 35 is mounted for rotation with play. The spherical shell contours 36 of the bearing mounts 37 form a spherical or spherical counter surface to the outer surface of the sliding elements 35. The sliding elements 35, together with the bearing mounts 37, form a ball joint for the spatial alignment of the sliding elements 35, such that they have degrees of rotational freedom about the X-axis as well as the Y-axis and the Z-axis. As mentioned above,The sliding elements 35 are made of a tribopolymer, which ensures sliding support in the spherical shell partial contours 36 of the bearing receptacles 37. As can be seen in particular from Figure 3, a holding block 33 with two spherical shell partial contours 36 of the bearing plate 32, spaced apart in the running direction, forms two bearing receptacles 37 spaced apart in the running direction, which encompass a guide section 21 of the guide rails 20. Whereas on the opposite side of the bearing plate 32, i.e., at a distance in the Z direction, two bearing receptacles 32 spaced apart in the running direction accommodate two sliding elements 35 (one each), spaced apart in the running direction, which interact in a form-fitting manner with the opposite guide section 21 of the guide rail 20. For this purpose, the sliding elements 35 each have sliding openings 38,which have a polygonal cross-sectional profile. The cross-sectional profile of the sliding openings 38 corresponds to the cross-sectional profile of the guide sections 21 of the guide rails 20, with the dimensions of the sliding openings 38 being selected such that they engage around the guide sections 21 of the guide rail 20 with some clearance. The sliding elements 35 each have a recess or slot through which a web of the carriage body 22 passes when the sliding bearing 30 is guided on the guide rail 20. As shown in Figure 3, the bearing plate 32 is designed as a skeleton structure for weight and strength reasons. The nuts 34, which interact with threaded bolts (not shown),are inserted into correspondingly contoured receptacles 39 of the holding blocks 33. These can, for example, be inserted there captive. The threaded bolts penetrating the bearing plate 32 from the opposite side can be guided by metal bushings that can absorb the preload forces of the screw fastening. Ma / mb March 26, 2024 Applicant: igus GmbH 51147 Cologne Plain bearings and plain bearing guides List of reference symbols 10 Plain bearing guide 20 Guide rail 21 Guide sections 22 Rail body 30 Plain bearing 31 Carriage 32 Bearing plate 33 Holding blocks 34 Nuts 35 Sliding elements 36 Spherical shell partial contour 37 Bearing receptacle 38 Sliding openings 39 Receptacles of the bearing plate 32,

Claims

1 K740273WO Ma / mb March 26, 2024 Applicant: igus GmbH 51147 Cologne Plain bearing and plain bearing guide Claims 1. Plain bearing (30) for guidance on a guide rail (20) preferably designed as a curved guide, wherein the plain bearing (30) comprises at least one carriage (31) with a bearing plate (32), with at least three bearing receptacles (37) provided on the bearing plate (32), in each of which a sliding element (35) with a continuous sliding opening (38) is arranged, wherein the sliding opening (38) has a cross-sectional contour complementary to a guide section (21) of the guide rail (20) and preferably encompassing the guide section (21) in a form-fitting manner, the sliding elements (35) are designed like spherical caps and are each mounted in a spherical receiving opening of the bearing receptacles (37), characterized in that at least some of the bearing receptacles (37), in particular all of the bearing receptacles (37),each of which is formed in several parts and is formed by first and second spherical shell partial contours (36) which complement each other to form a spherical contour for receiving a sliding element (35).

2. The plain bearing (30) according to claim 1, characterized in that the bearing receptacles (37) and / or the entire bearing plate (32), in particular the entire slide (31), are formed from a preferably thermoplastic material, wherein in particular the first spherical shell partial contours (36) are formed integrally with the bearing plate (32).

3. The plain bearing (30) according to claim 1 or 2, characterized in that at least one bearing receptacle (37), preferably two bearing receptacles (37), are each formed by a first spherical shell partial contour (36) of the bearing plate (32) and at least one second complementary spherical shell partial contour (36) of a holding block (33) that is fastened to the bearing plate (32).

4. The plain bearing (30) according to claim 3, characterized in that the holding block (33) is formed integrally from thermoplastic material. 5.Plain bearing (30) according to one of claims 3 or 4, characterized in that the holding block (33) has at least two spherical shell partial contours (36) which are formed as an integral part of the holding block (33). 3 6. A plain bearing (30) according to one of claims 3 to 5, characterized in that at least two holding blocks (33) extending in a running direction of the carriage (31) are provided, each forming a plurality of spherical shell partial contours (36) spaced apart from one another in the running direction and in particular are formed in one piece.

7. A plain bearing (30) according to one of claims 1 to 6, characterized in that the carriage (31) has four bearing receptacles (37) arranged in two opposite pairs spaced apart in the running direction, and in that all bearing receptacles (37) are stationary with respect to the bearing plate (32).

8. A plain bearing guide (10) comprising an elongate guide rail (20) designed as a curved rail that extends curved in at least one plane and comprises at least one plain bearing (30) having the features of one of claims 1 to 7. 9.Plain bearing guide (10) according to claim 8, characterized in that the curved rail (20) has at least one curvature in a vertical direction which extends substantially perpendicular to the running direction (Y-bend) and which is spanned by the axes (X; Y). 4, in which or parallel to which the running direction extends.

10. Plain bearing guide (10) according to one of claims 8 or 9, characterized in that the curved rail (20) is designed as a double rail with at least two guide sections (21) extending parallel to one another in the running direction and at a distance from one another, which are each encompassed by two sliding elements (35) of the carriage (31) arranged one behind the other at a distance from one another in the running direction.

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