Linear sliding-contact bearing

Abstract

The invention relates to a linear sliding-contact bearing (1) comprising a rail (2) and a carriage (3, 41) which has a complementary linear guide (4) and which interacts with the rail (2), the rail (2) being in the form of a single-piece double rail (5, 40) having two parallel rail elements (6, 7, 42, 43) in a rail plane (8), and the linear guide (4) of the carriage (3, 41) having two parallel linear guide elements (9, 10) matching the double rail (5, 40), wherein: a first of the rail elements (6, 42) and a first of the linear guide elements (9) form a guide unit (11); by means of the guide unit (11), a play-free or low-play sliding guide is provided; and the second rail element (7), together with the linear guide element (10), forms a support guide (12).

Description

[0001] Linear plain bearings

[0002] The invention relates to a linear plain bearing comprising an elongated rail and a carriage with a complementary linear guide which interacts with the rail, wherein the rail is designed as a one-piece double rail with two parallel rail elements and the linear guide of the carriage has two parallel linear guide elements.

[0003] Such a linear plain bearing can be used for the sliding guidance of a work device. Depending on the area of ​​application, a work device can have a wide variety of properties; for example, it can be an element of a machine tool. Another example is a work device in the form of a holding device, for example for a display, which is mounted so that it can be moved as easily as possible. It is always important that the linear plain bearing enables linear guidance of the work device attached to it along its rail with as little friction and wear as possible, while at the same time the work device should be reliably held on the rail. The invention relates, for example, to a linear plain bearing that can be used in vehicle construction, in particular in a commercial vehicle such as a tractor or a cleaning vehicle.In such a commercial vehicle, it is often desirable for a working device to be easily mounted in the cockpit so that it can be moved longitudinally. To ensure simple and reliable installation of the working device, the linear plain bearing is usually permanently installed in the vehicle. For this purpose, the rail of the linear plain bearing is fastened to a vehicle part, whereas the working device can be detachably fastened to the carriage. For this purpose, corresponding fastening devices are provided on the carriage and / or the working device.

[0004] In a linear plain bearing designed as a double rail with a matching carriage featuring parallel linear guide elements, the spacing between the parallel rail elements is always subject to a certain manufacturing tolerance, and the shape accuracy of the rail elements is also subject to a certain shape tolerance. The same applies to the spacing between the parallel linear guide elements and the shape tolerance of the linear guide elements, which must fit together with the rail elements.

[0005] A generic linear plain bearing designed as a one-piece double rail is known to those skilled in the art from DE 20 2021 105 329 U1. The known linear plain bearing has an actuating arm on one of the two linear guide elements, which actuating arm is arranged transversely to the longitudinal extent of the rail and can be moved in this transverse direction. The actuating arm can be fixed and released in the transverse direction. For fixing purposes, a spring element can be provided which interacts with the actuating arm and preloads it in the transverse direction against one of the rail elements. In this way, the freedom or lack of play of the sliding guide is adjusted in this prior art. The freedom or lack of play of the sliding guide that can be achieved in this way is considered to be too complex in terms of construction.

[0006] A general state of the art is known from DE 20 2004 016 094 U1, which includes an example of a linear plain bearing with a double rail that is not made in one piece but is composed of individual rails. For this, the individual rails must be screwed to a so-called base. With this state of the art, the freedom from or low backlash of the sliding guide of the linear plain bearing goes hand in hand with the screw mounting of the individual rails to the base. The parallel distance between the individual rails can be adjusted during screwing to the parallel distance between the linear guide elements, or parallelism or alignment errors of the rails that can occur during assembly and / or operation can be compensated for by means of the screw connection. This type of adjustment of the freedom from or low backlash is considered to be structurally complex and, in addition, the assembly work appears to be too high.

[0007] The invention is based on the object of proposing a structurally simplified linear plain bearing that can provide a desired freedom from play or low play and requires the least possible assembly effort.

[0008] According to the invention, the object is achieved in that a first of the rail elements and a first of the linear guide elements form a guide unit, in that a play-free or low-play sliding guide is provided by means of the guide unit, and in that the second rail element forms a support guide with the second linear guide element.

[0009] The solution requires only one rail element of the double rail and one linear guide element of the carriage to interact to provide lateral guidance for the linear plain bearing as a guide unit. The support guide, formed from the second rail element and the second linear guide element, essentially allows the absorption of a load in a direction orthogonal to the rail plane. It does not need to fulfill a lateral guidance function.

[0010] In the case of a state-of-the-art double rail manufactured in one piece, high demands are placed on the dimensional accuracy of the distance between the two parallel rail elements of the double rail, i.e. on the track width of the double rail. In addition, the demands on the parallelism of the rail elements are high. The design according to the invention can advantageously tolerate certain dimensional inaccuracies or larger tolerances in the track width of the double rail. The requirements on the parallelism of the two rail elements are also lower. Only one of two rail elements, together with an associated linear guide element, forms the guide unit, which alone assumes the exact directional guidance for the movement of the carriage on the double rail.The support unit, on the other hand, is designed to compensate for any dimensional deviations in the track width of the double rail and / or any deviations from ideal parallelism. The design therefore allows for larger dimensional and shape tolerances, or larger dimensional and shape tolerance zones, when manufacturing the double rail. This significantly reduces the effort and cost required to manufacture the double rail. The design according to the invention also improves the interchangeability of double rails with different carriages. While in the prior art the track width of the double rail had to match the track width of the carriage closely, i.e. both had to lie within a narrow tolerance zone, the tolerance zone can now be significantly enlarged.In series production, this means that a double rail fits together with a larger number of carriages whose track widths lie in a larger tolerance zone. Advantageously, at least one rail element of the double rail has a cross-section with an outer contour and at least one linear guide element of the carriage has a cross-section with a complementary inner contour and / or at least one rail element of the double rail has a cross-section with an inner contour and at least one linear guide element of the carriage has a cross-section with a matching outer contour.

[0011] The linear guide of the carriage is simply designed to slide on the rail elements of the double rail using its two linear guide elements. It is advisable to select different materials for the rail elements on the one hand and the linear guide elements on the other, resulting in a suitable material pairing, in particular so that the material of one of the elements has a significantly lower coefficient of friction than the material of the other element. It is advantageous if the material of the linear guide element is the one that has a lower coefficient of friction than the material of the rail element that forms the sliding surface.This has the advantage that the rail can be made of a material with good strength values, in particular a material with high flexural strength and a resistant surface, for example a metal, preferably aluminum or an aluminum alloy. A plastic, for example, can then be selected as the material for the linear guide element, which has the desired, comparatively lower coefficient of friction than the material of the rail.

[0012] A lateral clearance is advantageously provided between the linear guide element that forms part of the support guide and the associated rail element. With this built-in clearance, the support unit is easily configured to compensate for any dimensional deviations in the track width of the double rail and / or any deviations from ideal parallelism.

[0013] It is useful if the linear guide element which is assigned to the support guide has an inner contour and that the cross section of the inner contour is wider than the cross section of the outer contour of the assigned rail element.

[0014] It is often useful to provide the rail elements of the double rail with the outer contour and the linear guide elements of the carriage, as mentioned above, with the inner contour. This is the case, for example, when the double rail is arranged at the bottom and the carriage at the top. This is useful, for example, when the inner contour has a side opening, because the opening can then be arranged facing downwards. This prevents dirt from falling in and accumulating. For a double rail that is to be used in a suspended position, a reverse design can be advantageous, so that its rail elements are provided with the inner contour and the linear guide elements of the carriage are provided with the outer contour.

[0015] The rail element of the double rail, which is provided with an outer contour, conveniently forms a rail head.

[0016] Preferably, the rail head has a polygonal cross-section, preferably a circular cross-section with a cylindrical outer contour.

[0017] If the rail element belonging to the guide unit has an outer contour with a polygonal cross-section or a circular cross-section, a suitable linear guide element can be used to center the element on the rail element, thus ensuring precise centering and guidance of the entire carriage. This is possible because a polygonal cross-section and a circular cross-section each have lateral sliding surface areas that are arranged symmetrically to one another. A linear guide element sliding on these surfaces centers itself automatically.

[0018] Simply put, the rail head is supported by a web of the rail element.

[0019] The web is conveniently arranged on a base element of the double rail.

[0020] The rail element is designed as a single-piece rail or a single-piece double rail, and the webs and rail heads are preferably also integrated in one piece. On the double rail, the webs and rail heads are preferably arranged symmetrically to one another.

[0021] The one-piece rail is expediently produced by a primary forming or forming process that requires no mechanical post-processing. A rail made of metal, in particular aluminum or an aluminum alloy, can be produced as an extruded rail profile. A double rail produced in this way has two rail elements that are preferably symmetrical. The carriage, on the other hand, is provided with the linear guide, which has two differently designed linear guide elements, namely the first linear guide element, with which the guide unit can always be produced, and the second linear guide element, with which the support guide can always be produced.

[0022] Because the rail elements are symmetrical, the first linear guide element can be combined optionally with one or the other of the two rail elements. This inevitably always results in the guide unit. Likewise, the linear guide element can be combined optionally with one or the other of the two rail elements, always resulting in the support guide. The linear guide element, which is provided with an inner contour, advantageously has a C-shaped cross-section with a lateral opening. The lateral opening is expediently dimensioned such that the inner contour of the linear guide element encompasses the rail element over a circumferential range of 180° to 320°.

[0023] It is advantageous if the web of the double rail fits through the lateral opening of the C-shaped cross-section of the linear guide element.

[0024] A preferred embodiment is one in which the linear guide element that forms part of the guide unit has an inner contour with a circular cross-section. For the purposes of the invention, the cross-section is referred to as circular, even though it has a lateral opening.

[0025] Particularly preferably, the inner contour of the linear guide element that forms part of the support guide is provided with an oval cross-section. The oval cross-section is expediently provided with a lateral opening.

[0026] In a further improved embodiment, the oval cross-section of the inner contour of the linear guide element is composed of two partial circular arcs and one straight line. For the purposes of the invention, the cross-section is referred to simply as "oval," although it is designed as an open cross-section with only one straight line 29.

[0027] The intended play in the support guide preferably has a dimension range of 0.05 mm to 1.00 mm, in particular of 0.2 mm to 0.6 mm.

[0028] In a design with an oval cross-section of the inner contour of the linear guide element, which is composed of two semicircular arcs and two parallel straight lines of equal length, the play is simply defined by the length of a straight line of the oval, which must preferably lie within the dimensional range mentioned for the play.

[0029] A plain bearing element can be arranged between at least one of the rail elements and one of the linear guide elements. In this case, it is possible to dispense with the linear guide element as a whole having to be made of a material with a low coefficient of friction. It is then sufficient to simply form the plain bearing element from a material with a low coefficient of friction in order to provide low-friction contact with the rail element and smooth sliding along the rail element. For this purpose, the plain bearing element is preferably made of a plain bearing material, particularly preferably of a plain bearing plastic.

[0030] For the purposes of the invention, a plain bearing plastic is understood to be a preferably polymeric plastic which has a lower coefficient of friction than the surface of the rail element which serves as the sliding surface. These include, in particular, the thermoplastics polyethylene, polypropylene, polyacetal, polycarbonate, polyamide, polyvinyl chloride, polytetrafluoroethylene and, in the case of thermosets, phenolic resins. To further reduce friction, these plastics can contain lubricants, in particular fine-particle solid lubricants such as molybdenum disulfide or graphite. Such polymers are also referred to as tribopolymers, e.g. the product Iglidur®. Friction reduces wear and abrasion. These products are therefore particularly recommended when high purity is important. This is the case, for example, in the food and semiconductor industries, as well as in biochemical and microbiological applications.As mentioned, these polymer materials may also contain fillers and fibers, for example those made of plastic or textile, which improve the mechanical properties.

[0031] Advantageously, the plain bearing element has a sleeve-shaped plain bearing body with an inner contour, an outer contour, a central axis and a lateral opening.

[0032] The inner contour is preferably polygonal and particularly preferably hollow-cylindrical. The outer contour can also be polygonal and is preferably cylindrical.

[0033] It is helpful if the sliding bearing element provided on the guide unit side as well as the sliding bearing element provided on the support guide side each conforms to the cross section of the associated rail element.

[0034] In addition, it can be provided that the plain bearing element on the side of the guide unit also adapts with its outer contour to the cross section of the linear guide element.

[0035] The linear guide element then encompasses / encompasses the rail element indirectly, namely with the interposition of the plain bearing element. The plain bearing element, in turn, encompasses the rail element and is in direct sliding contact with the rail element. The linear guide element also encompasses the rail element but has no direct contact with it. The extent to which the plain bearing element encompasses the rail element expediently extends over a circumferential range of 200° to 320°. Preferably, the encompassed circumferential area of ​​the linear guide element and the circumferential area encompassed by the plain bearing element are identical or almost identical.

[0036] Advantageously, on the side of the support guide, the inner contour of the linear guide element has a width which is greater than the width of the outer contour of the plain bearing element, so that lateral play is formed with respect to the plain bearing element. If the inner contour of the linear guide element has an oval cross-section and the outer contour of the plain bearing element is cylindrical, then lateral crescent-shaped clearances are formed between the outer contour of the plain bearing element and the wide inner contour of the linear guide element. Parts of the outer contour of the plain bearing element then serve as a fastening side in order to bring the plain bearing element partially into contact with the inner contour of the linear guide element and to fix it, while other partial areas of the outer contour of the plain bearing element each define one side of the crescent-shaped clearance.The crescent-shaped clearances are thus provided on the outer side / outer contour of the plain bearing element, which serves solely to secure it within the linear guide element. The crescent-shaped clearances are thus located away from the inner contour of the plain bearing element, which serves as the plain bearing surface.

[0037] It is helpful if at least one of the linear guide elements has two guide sections arranged in a row, wherein the guide sections lie in a guide axis, wherein at least one of the linear guide elements has two support sections arranged in a row, and wherein the support sections lie in a support axis.

[0038] For precise, reliable linear bearings using linear plain bearings, it is helpful if each of the two guide sections has a certain length and if a certain distance is provided between the two guide sections. This makes it possible to provide an overall favorable length of the guide. Otherwise, a torque acting on the carriage could cause jamming due to the carriage tilting on the rail. Tilting would be favored by a guide that is too short. A suitable length for the guide section is in particular in the range of 0.1 to 1.5 times, in particular 0.2 to 1.0 times the track width of the double rail. A suitable distance between the guide sections arranged in a row is in particular in the range of 0.05 to 1.0 times, in particular 0.1 to 0.7 times, in particular 0.1 to 0.5 times the track width of the double rail.

[0039] A further benefit arises if at least one of the guide sections of the first linear guide element and at least one of the support sections of the second linear guide element is provided with a plain bearing element. The plain bearing element can simply have a length that lies in the range of the appropriate length of the guide section or the support section.

[0040] In a simple manner, all linear guide elements are provided with two guide sections arranged in a row, one behind the other, and each guide section is expediently provided with a plain bearing element. The plain bearing elements arranged in a row are spaced apart from each other at a distance identical to the aforementioned appropriate spacing provided for the guide sections.

[0041] It is also expedient to provide a connecting means for the plain bearing element, by means of which it can be connected to the linear guide element in a fixed position relative to the guide axis. The plain bearing element should move with the carriage and therefore be connected to the corresponding linear guide element of the carriage in a fixed position.

[0042] The connecting means can simply be an adhesive or a form-fitting connection.

[0043] As part of the positive connection, a locking recess can be provided in the inner contour of the linear guide element.

[0044] It is then advisable for the plain bearing element, as a complementary part of the form-fitting connection, to be provided with a projection on its outer contour which is designed to match the locking recess of the linear guide element.

[0045] In addition, the inner contour of the plain bearing element is provided with pocket-shaped recesses or groove-shaped recesses that extend parallel to its central axis or helically around the central axis. The pocket-shaped recesses or recesses can serve as dust or dirt chambers. Groove-shaped recesses can act as dirt channels through which dirt can escape at the front ends of the plain bearing element. The linear plain bearing designed in this way offers contamination-resistant, safe operation. In addition, only minimal running noise occurs during operation, even at high speeds of the carriage relative to the rail.

[0046] The invention is illustrated below by way of example in a drawing and described in detail with reference to several figures. They show:

[0047] Fig. 1 A front view of a linear plain bearing according to the invention,

[0048] Fig. 2 A front view of the carriage of the linear plain bearing according to Fig. 1,

[0049] Fig. 3 An enlarged detail according to III in Fig. 2

[0050] Fig. 4 A plan view of the carriage according to Fig. 2,

[0051] Fig. 5 is a perspective view of the linear plain bearing according to Fig. 1, Fig. 6 is a front view of an alternative embodiment of a linear plain bearing according to the invention,

[0052] Fig. 7 A front view of the carriage of the linear plain bearing according to Fig. 6,

[0053] Fig . 8 A front view of a plain bearing element

[0054] Fig . 9 A view according to IX in Fig . 8 .

[0055] According to the drawing, the linear plain bearing 1 according to the invention according to Fig. 1 comprises a rail 2 and a carriage 3 with a complementary linear guide 4 which interacts with the rail 2. The rail 2 is designed as a one-piece double rail 5 with two parallel rail elements, a first rail element 6 and a second rail element 7, both of which are arranged in a common rail plane 8. The linear guide 4 of the carriage 3 has two parallel linear guide elements, a first linear guide element 9 and a second linear guide element 10, which are arranged to match the rail elements 6 and 7 of the double rail 5.

[0056] The first rail element 6 of the double rail 5, together with the first linear guide element 9 of the carriage 3, forms a guide unit 11. This guide unit 11 provides a backlash-free or low-backlash sliding guide function. The second rail element 7, together with the second linear guide element 10, forms a support guide 12. The support guide 12 essentially enables the absorption of a load in a load direction L running orthogonal to the rail plane 8. The support guide does not have to fulfill a lateral guide function. An enlarged detailed view of the support guide is illustrated in Fig. 4. The rail elements 6 and 7 are designed as rail heads 6a and 7a, respectively. Both rail heads have a circular cross-section, which each forms a cylindrical outer contour 13 and 14, respectively.The rail head 6a is arranged with a web 15 on a base element 16 of the double rail 5, and the rail head 7a is arranged with a web 17 on the base element 16. The cylindrical outer contours 13 / 14 each serve as a sliding surface for the carriage 2. In order not to manufacture the entire carriage from a plain bearing plastic, plain bearing elements 18 and 19 made of plain bearing plastic are provided. These plain bearing elements are fixed in position with the linear guide elements 9 and 10 of the carriage 2.

[0057] The sliding bearing element 18 is sleeve-shaped with a circular or annular cross-section. However, the annular cross-section is not closed, but rather designed as a C-shaped open cross-section 20, so that a lateral opening 21 is formed. The web 15 of the double rail 5 fits through the lateral opening 21. The two sliding bearing elements 18 and 19 are identical and can, in principle, be interchanged.

[0058] The plain bearing elements 18 and 19 are identical. However, the type of mounting of the plain bearing element 19 in the linear guide element 10 differs from the mounting of the plain bearing element 18 in the linear guide element 9. This is illustrated in Figs. 2 and 3, which each show only the carriage, without the double rail.

[0059] According to Fig. 2, a sliding bearing element 18 and 19 is shown in each of the two linear guide elements 9 and 10 of the carriage. The linear guide element 9 has an inner contour 22 with a circular cross-section 23 with a lateral opening. The sliding bearing element 18 is arranged concentrically to the inner contour 22 of the linear guide element 9. Furthermore, the sliding bearing element 18 according to Fig. 1 is also arranged concentrically to the cylindrical outer contour 13 of the rail element 6.

[0060] The linear guide element 9 encompasses / encompasses the rail element 6 indirectly, namely with the interposition of the plain bearing element 18. Viewed in cross-section, both, i.e. the linear guide element 9 and the plain bearing element 18, both encompass the rail element over a circumferential area of ​​approximately 290°. This results in a positive connection between the linear guide element 9 and the rail element 6. Due to the positive connection, the carriage cannot be removed from the rail either laterally or upwards. It only has one degree of freedom for its movement, namely in the direction of the longitudinal extent of the rail that guides it.

[0061] While the plain bearing element 18 is fixed in a fixed position in the translational direction of the carriage on the linear guide element 9, it is in sliding contact with the sliding surface of the rail head 6a. In this way, the guide unit 11 is formed, which provides the play-free or low-play sliding guide function. In the sense of the invention, play-free is understood to mean a virtually play-free fit between the linear guide element and the rail element or a fit with a slight elastic preload between the sliding surfaces of the linear guide element and the rail element. With the latter measure, freedom from play can be guaranteed and it can be adjusted how freely or stiffly the carriage can be moved translationally on the double rail.A sliding guide function is understood to be low-play if it is equipped with a guide play between the sliding surfaces of the linear guide element and the rail element, which is a sufficiently low guide play that can prevent jamming due to tilting of the slide on the rail when a torque acts on the slide.

[0062] In contrast to the linear guide element 9, according to Fig. 2 the linear guide element 10 is provided with an inner contour 24 which has an oval cross section 25 with a lateral opening 26. The oval cross section 25 with the lateral opening 26 can be seen best in Fig. 3, which is composed of two partial circular arcs 27 and 28 and a straight line 29. In this way the support guide 12 is formed by means of the oval cross section 25. The oval cross section 25 as the inner contour of the linear guide element 10 has a width B which is greater than the outer diameter d of the plain bearing element 19. In this way the outer side / outer contour of the plain bearing element 19 has a lateral play 30 or 31 within the linear guide element 10. The size of the lateral play is determined by the length X of the straight line 29 of the oval cross-section 25 .Due to this design, the clearance 30 is formed as an almost crescent-shaped free space on the partial circular arc 27 and the clearance 31 as an almost crescent-shaped free space on the partial circular arc 28. In Fig. 3, the plain bearing element 19 is located centrally in the oval cross-section 25. The crescent-shaped free spaces each offer a lateral clearance 30 / 31 of X / 2, which corresponds to half the length of the straight line 29.

[0063] From Fig. 3, it can also be seen that the sliding bearing element 19 has a central axis 19a and groove-shaped recesses 32a, 32b, 32c, 32d arranged in this axial direction. The groove-shaped recesses can act as integrated dirt channels. Dirt particles can be wiped off the rail into a dirt channel and discharged via the dirt channel.

[0064] Advantageously, the built-in clearance of the support guide is located away from the inner contour of the plain bearing element. This allows the inner contour of the plain bearing element to fulfill its purpose as a plain bearing surface better than known designs that incorporate clearance in the area of ​​the inner contour of the plain bearing element.

[0065] Fig. 4 shows a plan view of the carriage 3. The linear guide element 9 of the carriage has two guide sections 33 and 34 arranged in series. The guide sections are aligned along a guide axis Fl. Each of the guide sections 33 and 34 is provided with a sliding bearing element 18 and 18', respectively, which are identical and interchangeable.

[0066] The guide section 33 and the guide section 33 have a length K that essentially corresponds to the length of the sliding bearing element 18. A distance M is provided between the two guide sections 33 and 34. The length K and the distance M are dimensioned such that jamming due to tilting of the carriage 3 on the rail 2 is counteracted.

[0067] The linear guide element 10 has two support sections 35 and 36 arranged in series. The support sections are also aligned. Each of the support sections 35 and 36 is provided with a respective sliding bearing element 19 and 19', which are identical to one another and interchangeable. They are also identical to and interchangeable with the sliding bearing elements 18 and 18' of the guide sections 33 and 34.

[0068] The sliding bearing elements 18 / 18' are fixedly connected to the linear guide element 9, and the sliding bearing elements are fixedly connected to the linear guide element 10. For this purpose, the linear guide element 9 is provided with locking recesses (A1, A2, A3, A4).

[0069] A top surface of the carriage 3 provides a mounting surface 37 for any suitable working device (not shown). The mounting surface is provided with four holes 37a-d.

[0070] Fig. 5 shows a perspective view of the linear plain bearing according to Fig. 1. The double rail 5 has a length which corresponds approximately to twice the length of the carriage 3. In the area of ​​the base element 16 of the double rail 5, a bore 38 is provided which can be used for mounting the double rail.

[0071] Fig. 6 shows a front view of an alternative embodiment of a linear plain bearing 1 according to the invention with a rail designed as a double rail 40 and a matching carriage 41. This embodiment differs from Fig. 1 in that the effective contours between the double rail and the carriage are reversed.

[0072] The double rail 40 is provided with rail elements 42 and 43, each having an inner contour which serves as a sliding surface, such as the hollow cylindrical inner contour 44 of the rail element 42.

[0073] To match this, the carriage 41 is provided with linear guide elements 45 and 46. The linear guide elements each have an outer contour that matches the inner contour 44. In the present example, in contrast to the previous example, the linear guide elements 45 and 46 of the carriage 41 are encompassed by the respective rail element 42 or 43. Viewed in cross-section, the encompassing here also covers a circumferential area of ​​approximately 290°. This has the effect that a positive connection is produced between the linear guide element 45 / 46 and the corresponding rail element 42 / 32. The positive connection means that the carriage 41 cannot be moved away from the rail either laterally or upwards. It only has one degree of freedom for its movement, namely in the direction of the longitudinal extent of the double rail 40 that guides it.

[0074] The linear guide element 45 has a cylindrical outer contour 47. A sliding bearing element 48 having a central axis is arranged between the outer contour 47 and the inner sliding surface of the rail element 42. During operation, the sliding bearing element 48 moves together with the carriage 41. For this purpose, it is fixedly connected to the outer contour 47 of the linear guide element 45. The sliding bearing element 48, in turn, has a cylindrical outer contour 49, which interacts with the inner sliding surface of the rail element 42 and slides thereon.

[0075] The cylindrical outer contour 49 is provided in the axial direction with four groove-shaped recesses 50a-d which extend parallel to the central axis and are open to the outside. The groove-shaped recesses 50a-d can act as dirt channels when the plain bearing element 48 is installed. The rail element 43 is arranged symmetrically to the rail element 42, but has an inner contour 43a with an oval cross-section 43b. The oval cross-section is wider than the hollow cylindrical inner contour 44 of the other rail element 42. Due to the greater width of the inner contour 43a, this offers a clearance S1 or S2 for the linear guide element 46 or for the intermediate plain bearing element G. The clearance S 1 / S2 is provided in the form of sickle-shaped clearances which are provided between the outer contour of the plain bearing element G and the oval inner contour 43a.

[0076] On an upper side, the carriage 41 is provided with a mounting surface 51 which can be used for attaching a working device.

[0077] Fig. 7 shows a front view of just the double rail 40 of the linear plain bearing according to Fig. 6. The inner contour 44 of the rail element 42 and the inner contour 43a of the rail element 43 can be seen, each of which forms a rail groove. The inner contour 44 has a circular cross-section, wherein the circumference is not completely closed, but has a lateral opening 52. The opening 52 is narrower than the diameter of the associated linear guide element 45. In the assembled state, the described positive connection therefore exists, which prevents the carriage 41 from accidentally becoming detached from the double rail 40. The oval cross section 43b of the inner contour 43a also has a lateral opening 43c, which is narrower than the diameter of the associated linear guide element 46 and also surrounds it in a form-fitting manner.

[0078] Fig. 8 shows a front view of a further example of a plain bearing element 60 which is suitable for the first exemplary embodiment of the invention. It has the same function and basic shape as the plain bearing elements of the first exemplary embodiment according to Figs. 1-3. The plain bearing element 60 shown here has an inner contour 61 which can be described simply as hollow and cylindrical and a central axis 64, and is provided with groove-shaped recesses 61a-f in the direction of this central axis. A lateral opening 65 with a width W is provided. In contrast to the plain bearing element of the first exemplary embodiment, only a different number of groove-shaped recesses is provided here, six. Their function is identical. The groove-shaped recesses 61a-f can act as integrated dirt channels when installed.Dirt particles can be scraped off a rail into a dirt channel and then discharged via the dirt channel.

[0079] On an outer contour 62, the sliding bearing element 60 has a plurality of projections 63a-g. The projections 63a-g serve to position the sliding bearing element 60 in a fixed position within the inner contour of a linear guide element, specifically in a form-fitting manner. For this purpose, the linear guide element must be provided with a suitable recess, for example, an annular groove (not shown) in its inner contour.

[0080] Fig. 9 shows a view in the direction of arrow IX indicated in Fig. 8. This illustration shows the central axis 64 of the plain bearing element 60, as well as its length K, the arrangement and extent of the projections 63a-g arranged on its outer contour 62. Furthermore, the width of the lateral opening 65 is shown.

[0081] List of reference symbols Linear plain bearing Rail Carriage Linear guide Double rail Rail element first a Rail head Rail element second a Rail head Rail plane Linear guide element 0 Linear guide element 1 Guide unit 2 Support guide 3 Cylindrical outer contour (first rail element) 4 Cylindrical outer contour (second rail element) 5 Web 6 Base element 7 Web 8 Plain bearing element 8 ' Plain bearing element 9 Plain bearing element 9 ' Plain bearing element a Central axis C-shaped cross section (plain bearing 18) Side opening (plain bearing 18) Inner contour (first linear guide element) Circular cross section Inner contour (second linear guide element) Oval cross section Side opening Partial circular arc Partial circular arc Straight line Play (sickle-shaped) Play (sickle-shaped) ad Groove-shaped recess Guide section Guide section Support section Support section Mounting surface ad Bore Bore Double rail Carriage Rail element Rail element a Inner contour b OvalCross section c lateral opening inner contour linear guide element linear guide element outer contour (linear guide element) plain bearing element outer contour (plain bearing element) 50a-d groove-shaped recesses

[0082] 51 mounting surface

[0083] 52 side opening (inner contour 44)

[0084] 60 plain bearing element

[0085] 61 hollow cylindrical inner contour

[0086] 61a-f groove-shaped recess

[0087] 62 Outer contour

[0088] 63a-g lead

[0089] 64 Central axis

[0090] 65 side opening

[0091] Al locking recess

[0092] A2 locking recess

[0093] A3 locking recess

[0094] A4 locking recess

[0095] B Width

[0096] D Outer diameter (plain bearing element)

[0097] Fl guide axis

[0098] G plain bearing element

[0099] K Length (sliding bearing element)

[0100] L Load direction

[0101] M Distance (between plain bearing element)

[0102] 51 crescent-shaped free space

[0103] 52 crescent-shaped free space

[0104] T2 supporting axle

[0105] W Width

[0106] X length

Claims

Claims Linear sliding bearing (1) comprising a rail (2) and a slide (3, 41) with a complementary linear guide (4) which interacts with the rail (2), wherein the rail (2) is designed as a one-piece double rail (5, 40) with two parallel rail elements (6, 7, 42, 43) in a rail plane (8) and the linear guide (4) of the slide (3, 41) has two parallel linear guide elements (9, 10) matching the double rail (5, 40), characterized in that a first of the rail elements (6, 42) and a first of the linear guide elements (9) form a guide unit (11), that a backlash-free or low-backlash sliding guide is provided by means of the guide unit (11), and that the second rail element (7) forms a support guide (12) with the second linear guide element (10).Linear sliding bearing (1) according to claim 1, characterized in that at least one rail element (6, 7) of the double rail (5) has a cross-section with an outer contour (13, 14) and at least one linear guide element (9, 10) of the slide (3) has a cross-section with complementary inner contour (22,. 24) and / or at least one rail element (42, 43) of the double rail (40) has a cross-section with an inner contour (43a, 44) and at least one linear guide element (45, 46) of the carriage (41) has a cross-section with a matching outer contour (49). Linear sliding bearing (1) according to claim 1 or 2, characterized in that a lateral clearance (30, 31, SI, S2) is provided between the linear guide element (10, 46) which is part of the support guide (12) and the associated rail element (7, 43). Linear sliding bearing (1) according to claim 3, characterized in that the linear guide element (10) which is associated with the support guide (12) has an inner contour (24), and that the cross-section of the inner contour (24) is further developed than the cross-section of the outer contour (14) of the associated rail element (7).Linear sliding bearing (1) according to any one of claims 2 to 4, characterized in that the rail element (6, 7) of the double rail (5) having an outer contour forms a rail head (6a, 7a). Linear sliding bearing (1) according to claim 5, characterized in that the rail head (6a, 7a) has a polygonal, preferably a circular cross-section with a cylindrical outer contour (13, 14). Linear sliding bearing (1) according to claim 5 or 6, characterized in that the rail head (6a, 7a) is formed by a web (15, 17) of the rail element. Linear sliding bearing (1) according to claim 7, characterized in that the web (15, 17) is arranged on a base element (16) of the double rail (5). Linear sliding bearing (1) according to any one of claims 2 to 8, characterized in that the linear guide element (9, 10) having an inner contour has a C-shaped cross-section (20) with a lateral opening (21). Linear sliding bearing (1) according to claim 9, characterized in that the web (15, 17) of the double rail (5) fits through the lateral opening (21) of the C-shaped cross-section (20) of the linear guide element (9, 10). Linear sliding bearing (1) according to one of claims 2 to 10, characterized in that the linear guide element (9) which belongs to the guide unit (11) has an inner contour (22) with a circular cross-section (23).Linear sliding bearing (1) according to claims 3 to 11, characterized in that the inner contour (22) of the linear guide element (10) belonging to the support guide (12) is provided with an oval cross-section (25). Linear sliding bearing (1) according to claim 12, characterized in that the oval cross-section (25) of the inner contour (22) of the linear guide element (10) is composed of two partial circular arcs (27, 28) and a straight line (29). Linear sliding bearing (1) according to any one of claims 3 to 13, characterized in that the intended clearance (30, 31, Sl, S2) in the support guide (12) is preferably between 0.05 and 1.00 mm, in particular between 0.2 mm and 0.6 mm. Linear sliding bearing (1) according to any one of claims 1 to 14, characterized in that a sliding bearing element (18, 18', 19, 19', 48, 60) is arranged between at least one of the rail elements (6, 7, 42, 43) and one of the linear guide elements (9, 10, 45, 46). Linear sliding bearing (1) according to claim 15, characterized in that the sliding bearing element (18, 18', 19, 19', 48, 60) has a sleeve-shaped sliding bearing body with an inner contour (61), an outer contour (62), a central axis (64) and a lateral opening (65).Linear sliding bearing (1) according to claim 15 or 16, characterized in that both the sliding bearing element (18, 18', 48) provided on the side of the guide unit (11) and the sliding bearing element (19, 19') provided on the side of the support guide (12) conform to the cross-section of the associated rail element (6, 7, 42). Linear sliding bearing (1) according to any one of claims 14 to 17, characterized in that the sliding bearing element (18, 18', 48) on the side of the guide unit (12) also conforms to the cross-section of the linear guide element (9, 45) with its outer contour (62). Linear sliding bearing (1) according to any one of claims 14 to 17. 18, characterized in that on the side of the support guide (12) the inner contour (24) of the linear guide element (10) has a width which is greater than the width or diameter of the outer contour (62) of the sliding bearing element (19, 19', 60) , so that a lateral clearance (30, 31, SI, S2) to the sliding bearing element (19, 19', 60) is formed. Linear sliding bearing (1) according to one of claims 1 to 19, characterized in that at least one of the linear guide elements (9, 45) has two guide sections (33, 34) arranged in series, and that the guide sections (33, 34) lie in a guide axis (Fl), and that at least one of the linear guide elements (10, 46) has two support sections (35, 36) arranged in series, and that the support sections (35, 36) lie in a support axis (T2).Linear sliding bearing (1) according to claim 20, characterized in that at least one of the guide sections (33, 34) of the first linear guide element (9) and at least one of the support sections (35, 36) of the second linear guide element (10) is provided with a sliding bearing element (18, 18', 19, 19', 48, 60, G). Linear sliding bearing (1) according to any one of claims 14 to 15. 21, characterized in that a connecting means is provided for the sliding bearing element (18, 18', 19, 19', 48, 60, G) by means of which it can be connected to the linear guide element (9, 10, 45, 46) in a positionally fixed manner relative to the guide axis (Fl, T2). Linear sliding bearing (1) according to claim 22, wherein characterized in that an adhesive or a positive locking connection is provided as the connecting means. Linear sliding bearing (1) according to claim 23, characterized in that a locking recess (Al, A2, A3, A4) is provided as part of the positive locking connection in the inner contour (22, 24) of the linear guide element (9, 10). Linear sliding bearing (1) according to claim 23 or 24, characterized in that the sliding bearing element (18, 18', 19, 19', 48, 60, G) is provided as a complementary part of the positive locking connection on its outer contour (62) with a projection (63a, 63b, 63c, 63d, 63e, 63f, 63g) which is designed to fit the locking recess (Al, A2, A3, A4) of the linear guide element (9, 10, 45, 46).Linear sliding bearing (1) according to one of claims 14 to 25, characterized in that the inner contour of the sliding bearing element (18, 18', 19, 19', 48, 60, G) is provided with pocket-shaped recesses or with groove-shaped recesses (32a, 32b, 32c, 32d, 61a, 61b, 61c, 61d, 61f) which are parallel to the central axis (64) or spirally around the central axis. (64) extend.

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