EP0006621A1 - A sliding swing bearing for bridges and similar structures comprising top, centre and base plate, and method for lining the curved upper surface of the base plate of such bearings - Google Patents

Abstract

A rocker-sliding bearing for bridges or similar structures and a method of lining the concave top side surface of a curved baseplate of a rocker-slider bearing wherein the rocker-slider bearing includes a flat top plate, an intermediate plate having a flat top side and a convex curved underside surface, a bedplate and a baseplate having a correspondingly concave curved top side surface in turn secured to the bedplate, the curved surface on the top of the baseplate including a lining of corrosion-resistant material and the curved surface of the intermediate plate including a lining with a low coefficient of friction relative to the highly corrosion-resistant material on the curved surface of the baseplate wherein the lining on the curved surface of the baseplate includes a preformed curved disc positioned on the baseplate and secured to the concave top side thereof.

Description

The invention relates to a tilting slide bearing for bridges or similar structures, with a flat top plate, an intermediate plate and a lower plate, the intermediate plate being displaceably mounted along an arched curved surface on the lower plate, the surface of the lower plate having a curvature attached to it provided with a correspondingly arched support made of corrosion-resistant material and on the underside of the intermediate plate a coating made of a material with a low coefficient of friction compared to the material for the support of the lower plate is attached. The invention further relates to a method for lining the concavely curved top of the lower plate of such a tilting slide bearing, in which a layer of good corrosion-resistant material corresponding to the curvature surface of the lower plate of the bearing is applied to this and attached to it.

In the case of tilting slide bearings for bridges or for other structures in which heavy loads have to be supported, the sliding surface is conventionally designed in the spherical plane in such a way that there is a friction combination of PTFE and hard chrome. Usually, the PTFE layer is chambered in the concavely curved upper side of the lower bearing part, while the curvature against the PTFE layer, which is convexly adapted to the concave curvature of the lower layer, is hard-chromed on its surface on the underside of the intermediate plate ("calotte") .

The solution has also already been attempted to insert the PTFE layer into the covex curved surface of the spherical cap and to provide the concave curved upper side of the lower bearing part with a hard chrome layer. It has been shown, however, that hard chrome plating of such spherical, in particular concave, surfaces is quite expensive and that the required uniformity of this layer can only be produced with difficulty. At the same time, a fairly large amount of manual effort for the necessary pre-polishing cannot be avoided before the chrome plating process and in particular also after the chrome plating. On the other hand, however, it is necessary to apply a corrosion-resistant layer with good rubbing properties.

Previously known approvals of bridge bearings by the Institut für Bautechnik, Berlin, only provide for the use of PTFE on one friction side and the application of a hard chrome layer on the other friction side. This means that so far the hard chrome In the case of bearings approved by the building authorities in Germany, all the difficulties that arose had to be accepted.

A tilting slide bearing according to the preamble of claim 1 is known (Swiss Patent No. 421 167), in which the curved surface of the lower plate is convex and the curved surface of the intermediate plate lying against it is correspondingly concave. Here, the corrosion protection layer is applied to the outwardly shaped (convex) spherical surface of the lower plate, which, from a manufacturing point of view, already poses considerable difficulties. However, this known bearing construction has so far not been successful in practical use: For example, Due to the center shift behavior of the center of gravity in such bearings, load initiation is often not sufficiently cheap. Furthermore, the lateral (linear) sliding movements to be absorbed by the flat sliding surface between the upper bearing part and the intermediate bearing plate when a deformation movement of the superstructure occurs, since the center of deformation of the superstructure does not coincide with the center of curvature of the sliding surface between the lower bearing part and the intermediate bearing part.

Proceeding from this, the object of the invention is to improve such a known tilting slide bearing in such a way that the disadvantages mentioned are largely avoided with economical manufacturing possibilities and simple assembly and nevertheless the application of a hard chrome layer on the spherical sliding surface of the lower bearing part is not necessary. Furthermore, the invention has for its object to provide a method for lining the spherically curved top of the lower plate for tilt slide bearings according to the invention.

The object on which the invention is based is achieved in a tilting slide bearing in accordance with the preamble of claim 1 in that the sliding surface of the support and the curved surface of the lower plate are concave and the arched support fastened to the lower plate consists of an austenitic sheet steel plate ground and polished on one side , whose uncut and polished surface faces the curved surface of the base plate. The thickness of the arched support is preferably between 0.75 and 5 mm, with a steel sheet thickness between 1 mm and 2.5 mm advantageously being used in most applications. The measures according to the invention can be carried out without great difficulty and they offer a flawless and safe solution to the problem addressed, while avoiding the difficulties associated with hard chrome plating of such concave-shaped surfaces. Moreover, the throughput times in the manufacture of such bearings can be shortened considerably, since, because of the pre-deformation of the support separate from the other bearing manufacture, the creation and processing of the individual parts can take place parallel to one another. The tilting slide bearings according to the invention can also be carried out very inexpensively, because the preformed arched supports to be used according to the invention (mostly designed as partial spherical disks) can be obtained commercially without difficulty as a purchased part.

The measures according to the invention impress with a particular simplicity of the lining, the use of polished and polished bearing plates that are polished on one side can be carried out and any kind of reworking of the concavely curved sliding surface of the support designed as a bearing surface is completely avoided; because the commercially available steel sheets already have the prescribed surface quality. The use of commercially available, one-sided ground and polished austenitic sheet steel disks not only eliminates the particularly difficult machining of concave curved sliding surfaces - which would have to be done, for example, in hard chrome plating - but also ensures that the curved surface is clad with a precise shape while being rigidly inserted and good mechanical fixability within the required tolerance range for radius deviations of a few tenths of a millimeter, which was previously not thought to be possible. Only the knowledge of the interaction of the various features claimed according to the invention could satisfactorily ensure the success desired according to the invention. A particularly secure fastening option in the sense of the operational safety to be required can be achieved in a slide bearing according to the invention in that the support, which is designed as a concave bulging disc, is glued to the lower plate and / or is screwed to the lower plate with countersunk screws in the outer region of its circumference. Advantageously, the concavely arched support is against the concave curved surface of the lower plate by means of an externally attached to its periphery on the lower plate Screwed retaining ring clamped, the inner surface, again preferably, may have a slope that runs against a correspondingly complementary slope on the outer circumference of the support and thereby presses the disc firmly onto the seat. Another advantageous embodiment can also consist in that a lower slope is provided on the inside of the retaining ring, which bears against a correspondingly complementary slope on the outer circumference of the support and which merges into a radially inwardly directed retaining ring projection against which the upper circumferential edge of the support rests. This results in a non-positive and form-fitting pressing of the disk against its base, and at the same time a centering effect can also be used. Another advantageous embodiment of the tilting slide bearing according to the invention also consists in the fact that the retaining ring presses the steel sheet disc in its edge region against the lower plate from above via a rounded inner bead. In all configurations in which the use of a retaining ring is provided, the same is preferably pressed against the lower plate by means of screws. A correspondingly large or variable pressing force can be applied against the pane to be clamped simply by a corresponding variation in the number of pressure screws. If the pane is not glued, but only screwed or otherwise pressed onto its base, it is advisable to apply an anti-corrosion layer on the concave, curved upper surface of the base plate to prevent rusting: a simple, preferably anti-corrosion layer can be achieved by fold coating with the so-called "base coat", which in one Range of about 50 gm layer thickness, thus twice a corrosion protection layer gives a total thickness of about 0.1 mm.

In a further advantageous embodiment of the inventive concept, the austenitic steel sheet used for the bulging disc consists of a chromium-nickel-molybdenum alloy, preferably the material with the material number 1.4401 according to DIN 17440 (material designation: X 5 Cr Ni Mo 18 10).

In most applications, the use of a pad with a thickness of 2.5 mm proves to be particularly favorable.

In order to keep the frictional conditions in the calotte friction surface particularly favorable, it is of great advantage if the material covering facing the preformed curved disc is made of PTFE on the underside of the intermediate plate and is provided with lubrication pockets on its surface facing the preformed disc, which in turn are completely filled with lubricant.

The bearing according to the invention impresses with the particular simplicity of the lining, while at the same time the desired design accuracies for such bearings can be maintained without difficulty even using commercially available sheet metal, and the selected fastening options shown are also completely satisfactorily effective with regard to the required operational reliability.

The method according to the invention is based on a method for lining the concavely curved top of the Bottom plate of such a tilting slide bearing according to the invention, in which a support made of a material which is resistant to corrosion is applied to and fixed to the curvature surface of the bottom plate of the bearing. According to the invention, a disk made of austenitic steel sheet ground and polished on one side and having a thickness between 0.75 mm and 5 mm is preformed corresponding to the concave curved surface of the lower plate of the bearing, but with a slight overmolding in its central area, the ground and polished side of the steel sheet which does not form the sliding surface of the disk which is intended to bear against the curved surface of the lower plate, and then further braces the concave preformed support in this way using a fastening acting on its outer area on the lower plate in its end position on the concave curved surface of the lower plate. The method according to the invention can be carried out simply and quickly, and all suitable fastening options can be provided as the fastening. Advantageously, however, the outer area is pressed against the lower plate by means of a retaining ring for the bracing fastening of the support; further preferably, the support on the lower plate, if necessary additionally, can also be glued and / or screwed and / or welded.

In the invention, all difficulties which arise in connection with and in the application of a hard chrome surface layer carried out up to now are reliably avoided, and at the same time a considerably more economical production is possible. The bearings according to the invention can also be produced more quickly and with a particularly high degree of uniformity, at the same time that of the plane Lateral deflections of the top plate to be accommodated in the event of a deformation movement of the superstructure are smaller than, for example, in the case of slide bearings of the generic type and, likewise, the load introduction into the bearing can be kept more favorable than in the case of the generic tilting slide bearing due to the center shift behavior of the center of gravity. Furthermore, the bearings according to the invention can also be produced much more quickly than when applying a hard chrome layer and can be produced with particularly great uniformity (particularly small tolerances).

In an advantageous embodiment of the method according to the invention, only those shell sheets which have a thickness of 2 mm or less, preferably of 1 mm or less, are used in an adhesive bond between the shell and the base plate. This allows a good post-deformation possibility to be achieved during the assembly and bonding process. If thicker sheets are used here, the post-deformation forces to be applied may be relatively high during assembly, so that the load-bearing capacity of the adhesive layer may be exceeded and this could lead to undesired detachment phenomena. If, as shown, thinner sheet thicknesses are used, in particular in the specified areas, the preformed shell is simply attached to the base using a suitable metal adhesive and, as has already been pointed out, can also be added in its arched shape after the adhesive has set the outer edges can also be held down with countersunk screws (or by using a retaining ring, by welding or similar). When using an adhesive, additional pretreatment of the steel surface is also necessary Prevention of rusting not necessary.

However, if no adhesive is used for the attachment, it is recommended to apply a double primer coat with a total thickness of about 0.1 mm before the shell is inserted onto the curved surface of the base plate for corrosion protection.

• Fig. 1 eine seitliche Prinzipdarstellung eines erfindungsgemäßen Kippgleitlagers;
• Fig. 2 eine vergrößerte Detaildarstellung der Einzelheit A aus Fig. 1;
• Fig. 3 eine Draufsicht auf eine für die Auskleidung der konkaven Krümmungsfläche des Unterteiles eines erfindungsgemäßen Lagers einsetzbare vorgeformte Scheibe;
• Fig. 4 bis 6 prinzipielle Detaildarstellungen für die Einspannung der vorgeformten Scheibe mittels eines Halteringes gegen die Unterplatte mit verschiedenen Haltering-Formen.

The invention is explained in more detail below in principle on the basis of the drawing. Show it:

• Figure 1 is a schematic side view of a tilting slide bearing according to the invention.
• FIG. 2 shows an enlarged detailed illustration of detail A from FIG. 1;
• 3 shows a plan view of a preformed disk which can be used for lining the concave curvature surface of the lower part of a bearing according to the invention;
• 4 to 6 basic detailed representations for the clamping of the preformed disc by means of a retaining ring against the lower plate with different retaining ring shapes.

In the tilting slide bearing shown in Fig. 1, an upper plate 1 can be seen, which is flat on its underside and with a good corrosion resistance Support layer 2 is provided. This support layer 2 can consist of a suitable stainless steel sheet as well as a hard chrome layer.

The intermediate plate 4 of the bearing is flat on its upper side and there has a PTFE layer in a chambered receptacle, which protrudes slightly beyond the flat surface of the intermediate plate 4 and is in (frictional) contact with the support 2 on the upper plate 1. The intermediate plate 4 is spherically curved on its underside, in the exemplary embodiment shown it is spherical. A suitably shaped PTFE plate 5, which is provided against a non-rusting support in the correspondingly concavely shaped curvature surface arranged on top of a lower plate 7, is in turn embedded in the chambered receptacle. This "anti-corrosion layer" is designed in the form of a concave configuration of the curved surface of the lower plate 7, which bulges 6, which on the lower plate 7 in the example shown with an adhesive layer 10 (FIG. 2) and in its edge region additionally in bores 12 (FIG 3) recessed countersunk screws 9 (Fig. 1 or Fig. 2) is attached. The lower plate 7 in turn is then arranged on a suitable foundation 8, which is not shown in FIG. 1.

As can be seen from Fig. 2, the chambered PTFE friction layer 5 is provided in the curved lower surface of the intermediate plate 4 on its side facing the lower plate with lubricant-filled lubrication pockets 11, by means of which permanent lubrication of the spherical sliding surface can be ensured.

• Zunächst wird die Unterplatte 7 in ihrer genauen Formgebung hergestellt, wobei (ggf. auch gleichzeitig und unabhängig hiervon) aus einem laufenden, handelsüblich erhältlichen, auf der Oberfläche bereits polierten und geschliffenen Metallblech die erforderlichen vorgeformten gewölbten Schalen 6 durch ein geeignetes Verformungsverfahren hergestellt werden. Diese gewölbten Schalen werden sodann in die konkav ausgebildete Krümmungsfläche der Unterplatte 7 eingelegt und dabei dann geeignet miteinander verbunden, z.B. durch eine vorher dort oder auf der Unterseite der Schale aufgetragene Klebstoffschicht, ggf. auch durch im Randbereich der vorgewölbten Schale angeordente Senkkopfschrauben (welche die alleinigen Befestigungsmittel oder auch zur Klebung zusätzliche Befestigungsmittel darstellen können).

The surface of the preformed shell 6, ie the side of the shell 6 which faces the PTFE layer attached to the intermediate plate at the bottom, is ground and polished. The concave surface of the lower plate 7 is lined as follows:

• First, the lower plate 7 is produced in its exact shape, the necessary preformed curved shells 6 being produced from a running, commercially available, already polished and ground metal sheet on the surface (if necessary also simultaneously and independently of this) by a suitable shaping process. These curved shells are then placed in the concave curved surface of the lower plate 7 and then suitably connected to one another, for example by an adhesive layer applied there beforehand or on the underside of the shell, possibly also by countersunk screws arranged in the edge region of the curved shell (which are the only ones) Fasteners or can also represent additional fasteners for gluing).

In the case of the tilting slide bearing shown in the figures, in the interest of good clarity, the depiction of measures which are required or customary in such tilting slide bearings and are familiar to any person skilled in the art, such as lateral seals or the like, has been omitted.

The round shape shown in FIG. 3 for a disk 6 represents only one possible embodiment of such a disk. In principle, it is possible to use any suitable, also non-round shape for the disk 6, in particular, for example, a polygonal shape (eg octagonal), the sides each represent the tangent of the inner use diameter of the disk 6.

4 to 6 are (in principle) various options for mechanically lowering the disk 6 against its bearing surface by using a Retaining ring 13 shown, which can be screwed against the lower plate 7 via screws 9 '. This purely mechanical clamping of the pane 6 no longer requires the pane 6 to be glued to the base 7, which is why there may be a risk of under-rusting here. For this reason, a corrosion-preventing layer 17 is (at least) applied to the lower plate 7 in the area of the contact surface of the lower plate 7 for the pane 6. This corrosion protection layer 17 is carried out as a double application of the so-called “base coat”, which is in a range of approximately 50 μm layer thickness.

In the embodiment of FIG. 4, the retaining ring 13, which is clamped on the lower plate 7 by means of screws 9 ′, is provided with a bevel 14 lying on the inside at the bottom thereof, which bears against a corresponding bevel at the end of the layer 6. If the retaining ring 13 is now tightened against the lower plate 7 by means of the screws 9 ', then an increasing tensioning of the shell 6 against the lower plate 7 is achieved due to the wedge action between the bevels of the retaining ring 13 and the shell 6 until a complete adaptation to the base and there is an absolutely tight fit.

The retaining ring 13 in the exemplary embodiment according to FIG. 5 in turn has a bevel 14 at the bottom on its inside, but this time it is not (as in the exemplary embodiment according to FIG. 4) considerably longer than the bevel of the bulging disk 6; rather, the bevel 14 here merges directly at the upper outer edge of the curved disc 6 into a radially inwardly projecting shoulder 15 of the retaining ring 13, so that when the retaining ring 13 is screwed onto the lower plate 7, the wedge effect on the bevel 14 (similarly) as in the example according to FIG. 4), at the same time, however, due to the angle formed between the bevel 14 and the projection 15, an upward deflection of the disc 6 is prevented by contacting the projection 15 and thereby additionally a depression of the end of the disc 6 the facility is achieved there.

Also in the embodiment shown in FIG. 6, in the end region of the bulging disc 6, the latter is forced down by a rounded lower inner bead 16 of the retaining ring 13.

In the exemplary embodiments shown in FIGS. 4 to 6, the bulging disk 6 is preformed before it is applied to the lower plate 7 in such a way that a slight overmolding is formed in its center (ie the radius of curvature there is somewhat smaller than the corresponding radius of curvature on the lower plate 7). If the arched disc 6 preformed in this way is then placed on the lower plate 7, the end region of the plate 6 protrudes somewhat from the associated contact surface. This protrusion is then broken down again by mechanical pressing via the retaining ring 13, which not only leads to the end region of the disk 6 also resting against the receiving surface on the lower plate 7, but at the same time also forms a tension build-up within the plate 6 such that a particularly firm and full contact of the disc 6 on the base 7 is ensured.

Claims (16)

1. Tilt slide bearing for bridges or similar structures, with a flat top plate (1), an intermediate (4) and a lower plate (7), the intermediate plate (4) being slidably supported along an arched curved surface on the lower plate (7) Provide the surface of the lower plate (7) with a support (6) made of corrosion-resistant material attached to it and curved according to its curvature and on the underside of the intermediate plate (4) a coating (5) made of a material with the material of the support (6) Lower plate (7) with a low coefficient of friction is attached, characterized in that
that the sliding surface of the support (6) as well as the curved surface of the lower plate (7) is concave and the arched support (6) attached to the lower plate (7) consists of a polished and austenitic sheet steel disc on one side, the non-ground and polished surface of the curved surface of the lower plate (7) is facing. 2. Tilting slide bearing according to claim 1, characterized in that the bulging, ground and polished austenitic sheet steel disc (6) has a thickness between 0.75 mm and 5 mm, but preferably between 1 mm and 2.5 mm. 3. tilting slide bearing according to claim 1 or 2, characterized in that the as a concave bulging disc (6) formed support on the lower plate (7) is glued or screwed to the lower plate (7) in the outer area of its circumference with countersunk screws (9). 4. Tilting slide bearing according to one of claims 1 to 3, characterized in that the concavely arched support (6) against the concave curved surface of the lower plate (7) by means of a nozzle attached to its periphery and screwed onto the base plate (7) (13) is tense. 5. Tilting slide bearing according to claim 4, characterized in that the inner surface of the retaining ring (13) has a slope (14) which runs against a correspondingly complementary slope on the outer circumference of the support (6). 6. Tilting slide bearing according to claim 4, characterized in that on the inside of the retaining ring (13) a lower slope (14) is provided which bears against a correspondingly complementary slope on the outer circumference of the support (6) and the radially above in a internally directed retaining ring projection (15), against which the upper peripheral edge of the support (6) abuts. 7. tilting slide bearing according to claim 4, characterized in that the retaining ring (13) on a rounded inner bead (16) presses the sheet steel plate (6) in its edge region from above against the / lower plate (7). 8. tilting slide bearing according to one of claims 4 to 7, characterized in that on the concavely curved top of the lower plate (7) has a corrosion protection layer (17), preferably in one Form is applied as a double coating of a base coat. 9. tilting slide bearing according to one of claims 1 to 8, characterized in that the austenitic steel sheet of the support (6) consists of a chromium-nickel-molybdenum alloy. 10. Tilting slide bearing according to one of claims 1 to 9, characterized in that the support (6) has a thickness of 2.5 mm. 11. Tilting slide bearing according to one of claims 1 to 10, characterized in that the arched support (6) facing material covering on the underside of the intermediate plate (4) consists of polytetrafluoroethylene and on its surface facing the support (6) with lubricant-filled lubrication pockets (11 ) is provided. 12. A method for lining the concave curved top of the lower plate of a tilting slide bearing according to one of claims 1 to 11, in which a support made of corrosion-resistant material of the curved surface of the lower plate of the bearing is applied accordingly to this and attached to it, characterized in that a Disc made of austenitic steel sheet, ground and polished on one side, with a thickness between 0.75 mm and 5 mm corresponding to the concave curved surface of the lower plate of the bearing, but preformed with a slight overmolding in its central area, whereby the ground and polished side of the steel sheet does not for contact with the curved surface of the lower plate certain sliding surface of the Forms disc, and that the concave preformed in this way is then clamped to its end position on the concave curved surface of the lower plate using a fastening acting on its outer area on the lower plate. 13. The method according to claim 12, characterized in that for the tensioning fastening of the layer, the outer region thereof is pressed against the lower plate by means of a retaining ring. 14. The method according to claim 12 or 13, characterized in that the support is additionally glued and / or screwed to the lower plate. 15. The method according to claim 14, characterized in that only a sheet metal of a thickness of 2 mm or less, preferably of 1 mm or less, are used in a bond between the support and the base plate. 16. The method according to claim 12 or 13, characterized in that a double primer coat is applied in a total thickness of about 0.1 mm before the insertion of the support on the curved surface of the curvature of the lower plate for corrosion protection.

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