CRANE BEAM

Abstract

Crane girder (1) for a crane (3), wherein the crane girder (1) comprises a hollow profile (4) having an outer wall (6) enclosing a cavity (5) and extends longitudinally, and the outer wall (6) of the crane girder (1), as seen in a cross-section through the crane girder (1), has a shape which bulges outwards at least in some regions in order to reduce air resistance, wherein the outer wall (6), as seen in the cross-section through the crane girder (1), has two sections (10, 11) facing one another with an outwards bulging shape, which are joined together by means of two straight wall sections (12) of the outer wall (6), said straight wall sections face one another, and the crane girder (1) has at least one running surface (13) for at least one running wheel (14) of a trolley (15) of a lifting tool of the crane (3), wherein the sections (10, 11) facing one another with an outwards bulging shape point upwards and downwards in an operating position of the crane girder and the straight wall sections (12) delimit the crane girder (1) on the sides.

Description

Crane girder for a crane The present invention relates to a crane girder for a crane, wherein the crane girder has a hollow profile with an outer wall enclosing a cavity and is elongated, and the outer wall of the crane girder, viewed in a cross-section through the crane girder, has a shape that bulges outwards at least in some areas to reduce air resistance, wherein the outer wall, viewed in a cross-section through the crane girder, has two opposing sections with an outward bulging shape, which are connected to each other by means of two opposing straight wall sections of the outer wall, and the crane girder has at least one Running surface for at least one running wheel of a trolley of a lifting device of the crane. For crane girders, especially for large cranes or cranes that have to bear heavy loads, such as gantry cranes, bridge cranes or jib cranes, the Crane girders in the prior art are frequently designed as hollow profiles in so-called box girder construction. This hollow profile has a cavity and an outer wall enclosing this cavity. In the prior art, the outer walls are generally assembled from flat sheets in a rectangular cross-section. To prevent deflection or bending of the sheets as a result of To prevent stability problems caused by compressive or shear stress, the prior art typically involves attaching reinforcing strips, known as buckling stiffeners, to the inside of the outer wall of the crane girder. These stiffeners extend longitudinally along the girder and are usually welded on. The number of buckling stiffeners can vary considerably, typically ranging from 2 to 20 depending on the girder size. The disadvantage of these stiffeners is that they increase both the weight of the crane girder and the manufacturing effort. DE 37 23 324 A1 discloses a crane girder in the form of a box girder structure where, to increase torsional stiffness, the two lateral web plates are designed as concave, inwardly curved shells. German patent application DE 1 1 17 279 B discloses a crane girder having a circularly curved hollow profile, wherein two opposing sections with outwardly bulging shapes are connected to each other by means of straight wall sections. The straight wall sections form a downwardly open slot in which the crane girder's guide rails and trolley are arranged. US Patent 3,294,252 A shows crane girders with a circular cross-section, with the respective running surfaces arranged in a central area at the apex of the circular cross-section. EP 0 194 615 A1 shows a crane girder with a circular cross-section for cantilevered trolleys on one side. The forces are introduced into the crane girder tangentially, which is why the crane girder is subject to bending stress as well as a is subject to torsional stress. The object of the invention is to provide a crane girder of the type mentioned above. to improve it in such a way that the drive power required to move the crane girder is as low as possible, while generating large forces with low Deformation of the crane girder can be initiated into the crane girder. According to the invention, it is proposed that the mutual Opposing sections with outwardly bulging shapes point upwards and downwards in an operating position of the crane girder, and the straight wall sections extend the crane girder to the sides in the operating position. limiting, wherein the wall sections extend vertically and the running surface is arranged and / or supported on, preferably on, one of the straight wall sections of the outer wall. The outward bulging shape of the outer wall, at least in some areas, deviating from a rectangular form as seen in the cross-section through the crane girder, results in an aerodynamic improvement. This reduces the wind load acting on the crane girder when it is moved by lowering the air resistance. Consequently, the drive power required to move the crane girder can be significantly reduced. The crane girders according to the invention are of a type Box construction manufactured so that it too has a hollow profile with a The outer wall enclosing the cavity has a shape that bulges outwards, at least in some areas, to reduce air resistance. This shape could also be described as having a more aerodynamic shape, at least in some areas. The sections of the crane girder that point upwards and downwards in its operating position can be designed as so-called upper and lower chords. These can then be used to absorb and transfer the loads generated by the application of the load to the crane girder and by the crane girder's own weight. Bending moments are used. Particularly in such designs, the outwardly bulging shape achieves exceptionally high stability with a relatively low weight of the crane girder. The straight wall sections, which form the two opposing Sections with an outwardly curved shape can also be called bridges or side bridges. In addition to improving aerodynamics or reducing the The crane girder's outward-bulging shape, which reduces air resistance, also results in improved structural stability. This outward bulging shape of the outer wall increases the crane girder's stability compared to a rectangular cross-section of the outer wall, assuming the same material and wall thickness. This eliminates, or at least partially eliminates, the need for reinforcing elements such as the aforementioned stiffening elements on the outer wall. This achieves greater stability and thus load-bearing capacity of the crane girder without increasing its weight. However, it should be noted that if this is necessary in specific designs, for example, for structural reasons to support the outer wall or for other purposes, the structural integrity of the girder may be compromised.For reasons of simplifying the production of the crane girder, it seems sensible to also arrange internal walls within the cavity surrounded by the outer wall. Preferred variants of a crane girder according to the invention with the aforementioned running surface advantageously run essentially horizontally in the operating position of the crane girder. "Essentially horizontal" in this context means... The relationship is preferably understood to be the horizontal itself and a deviation from it of a maximum of + / - 5°, preferably + / - 1°. Crane girders on which the wheels of the trolley of the crane's lifting device are supported are often also referred to as the main girders of the crane. The invention offers the advantage with such main girders that the wheel loads of the trolley's wheels can be readily absorbed by the crane girder. By supporting the running surface or rail on the wall sections, which are preferably arranged vertically when viewed in the operating position, it is particularly easy to optimally transfer the wheel loads of the trolley's wheels into the crane girder. In particular, with such designs, it is possible to transfer the wheel loads into the crane girder at any point along the running surface, even if there is no bulkhead or other additional substructure present. The crane girders according to the invention are elongated. That is, their length is significantly greater than their width and thickness. Preferred embodiments of the crane girders according to the invention, as is known in the prior art, provide that so-called bulkhead plates are arranged at certain intervals along the longitudinal extent of the crane girder in the cavity, against which the outer wall is supported or attached. The bulkhead plates are advantageously arranged so that they are perpendicular, i.e., orthogonal to the direction of the longitudinal extent of the crane girder. The spacing of the bulkhead plates can be selected as required. A further advantage of the outward-bulging shape of the crane girder's outer wall, at least in some areas, is that it significantly reduces the generation of noise or similar disturbances caused by wind and / or vibration compared to conventional crane girders with a rectangular cross-section of the outer wall. Furthermore, the invention also increases the stability of the crane girder and / or crane against tipping over, for example, in the event of a storm. Particularly preferred embodiments of the invention provide that the outer wall of the crane girder, viewed in a cross-section through the crane girder, has a shape that bulges outwards everywhere. The crane girder is moved, usually by the crane, in at least one direction relative to the surrounding air. This can involve moving the entire crane, including the crane girder, and / or moving the crane girder relative to other crane components. To minimize the In preferred embodiments of the invention, the air resistance of the crane girder during movement in the direction of movement is provided such that a The width of the outer wall of the crane girder is limited parallel to the direction of movement by a first end and a second end of the width of the outer wall, and, viewed in cross-section through the crane girder, the distance measured orthogonally to the direction of movement between opposing sections of the outer wall increases at least partially from at least one end of the width, preferably from both ends of the width, towards a central area of ​​the cavity. Of course, there can also be embodiments in which the crane girder can be moved in two or more directions. In such variants, the above applies to at least one of the directions of movement and preferably for the direction of movement in which the The crane girder is most frequently moved, or where the greatest wind load is expected. Since a key concern is reducing air resistance, the direction of movement ultimately always involves a relative movement between the The crane girder and the surrounding air. When determining the aforementioned direction of movement, the prevailing local wind direction can therefore also be taken into account. In this sense, the above principle is even applicable to crane girders or cranes that are fixed in place. The outwardly bulging shape of the outer wall could also be described as an outwardly curved shape, whereby this outwardly bulging or curved shape can be rounded, but does not have to be. Thus, there are a wide variety of designs for the outwardly bulging shape of the outer wall, at least in some areas. For example, it is possible that the outwardly bulging or curved shape of the outer wall, viewed in cross-section through the crane girder, is rounded.Alternatively, or in other areas of the outer wall, it is also possible that the shape of the outer wall, which bulges outwards at least in some areas, is polygonal in cross-section through the crane girder. An upwardly bulging shape also has the advantage that little or no rainwater or other precipitation can collect on the crane girder, thus preventing or minimizing the additional load on the crane girder from rainwater accumulating on it. To avoid the additional load of precipitation, it can also be designed that the crane girder is positioned in the The crane is positioned in its operating position with a slight longitudinal inclination. The sections of the crane girder's outer wall, as seen in the aforementioned cross-section, which bulge outwards, can be partially circular arcs or otherwise curved. As mentioned above, polygonal profiles or other forms of bulging are also conceivable. Preferred embodiments of the invention provide that a The width extent of the outer wall of the crane girder parallel to the direction of movement is greater or less than the thickness extent of the outer wall of the crane girder perpendicular to the direction of movement. The width extent and the The thickness extent refers to the maximum dimension of the outer wall in the respective direction. The longitudinal extent of the crane girder, the width extent of the outer wall, and the thickness extent of the outer wall are advantageously orthogonal to each other. If the width extent of the outer wall in a horizontal direction, as seen in the aforementioned cross-section, is greater than the thickness extent in a vertical direction, this is generally particularly advantageous in terms of... Reduction of wind load. Designing the thickness of the outer wall in the vertical direction to be greater than its width in the horizontal direction can be advantageous if particularly high static requirements are placed on the crane girder. In preferred embodiments, it is provided that the Thickness of the outer wall in the vertical direction, as seen in the aforementioned cross-section of the crane girder, is between 50 and 80% of the width.The width of the outer wall in the horizontal direction is, for large cranes such as gantry or bridge cranes, where the crane girders according to the invention are used as main girders with their longitudinal direction usually oriented essentially horizontally, the width of the outer wall in the horizontal direction, viewed in the aforementioned cross-section through the crane girder, can be from 2.5 m to 10 m, preferably from 3 m to 6 m. The length of the crane girders can, for example, be from 10 m to 150 m. If straight wall sections or webs are provided in the outer wall, their thickness in the operating position, viewed in the vertical direction, is advantageously between 20% and 60%, preferably between 30% and 40%, of the aforementioned thickness of the outer wall in the vertical direction. Even if, in preferred embodiments, the width of the outer wall runs in the horizontal direction and the thickness of the outer wall runs in the vertical direction, this is, of course, not mandatory. In preferred designs, the outer wall, viewed in cross-section through the crane girder, is at least symmetry-wise with respect to one axis. Axis-symmetric. The aforementioned direction of movement is advantageously parallel to the or one of the axes of symmetry. The cross-section through the The crane girder is preferably considered in a plane to which its longitudinal extent is normal or orthogonal. The outer wall of the crane girder is preferably made partially or entirely of steel. For the production of the For the outer walls, steel sheets with thicknesses between 8 and 20mm are preferably used. Crane girders according to the invention can be used with a wide variety of crane types. In addition to the crane girder itself, the invention also relates to a crane which has at least one crane girder according to the invention. Particularly preferably, this is a gantry crane, a bridge crane, or a jib crane. The crane girders according to the invention can be essentially vertical supports, e.g., for connecting a crane's chassis to a main girder, or essentially horizontal main girders. In the case of a gantry crane or bridge crane, the crane according to the invention can have a single, two, or more main girders in the form of crane girders according to the invention. Further features and details of preferred design forms of the The invention is shown in the attached illustrations in the form of various Variants are shown. Figures 1 to 3 show different configurations of cranes with crane girders according to the invention; Fig. 4 shows a cross-section through the crane girder shown in Figs. 1 to 3, and Figs. 5 and 6 show alternative embodiments thereof. Fig. 1 shows a crane 3 in the form of a gantry crane, in which the crane girder 1 designed according to the invention is configured as a main girder arranged essentially horizontally in the operating position shown. This main girder 1 has, as shown more clearly in Fig. 6, a hollow profile 4 in which the cavity 5 is enclosed by an outer wall 6. The outer wall 6 of the crane girder, as can be clearly seen in the cross-section through the crane girder 1 according to Fig. 6, is designed with a shape that bulges outwards, at least in some areas, to reduce air resistance. In the specific embodiment, the sections 10 and 11 forming the upper and lower chords are formed with an outwardly bulging shape. The outer wall 6 is provided with a bulging shape. Towards the sides, the outer wall 6 consists of the straight wall sections 12. The main beam 1 according to Fig. 1 supports the Trolley 15, to which a lifting device of the crane (not shown here, but known per se) is attached. The trolley 15 is movable in the longitudinal direction 27 along the crane or main girder 1. For this purpose, the crane girder 1 in the first embodiment shown has two running surfaces 13 on which the wheels 14 of the trolley 15 run. As can be seen particularly well in Fig. 6, the running surfaces 13 are designed as rails. The running surfaces or rails 13 are supported on the straight wall sections 12, which could also be referred to as webs or side webs, of the outer wall 6. Particularly because of the vertical extent of the straight wall sections 12, very large loads can be transferred into them without this resulting in a significant Deformation of crane girder 1 occurs. Crane girder 1 is in this In this exemplary embodiment, the two yokes 22 are suspended. The yokes 22 are in turn supported on the chassis 23 by supports 21, as in the prior art. Above the chassis 23, the supports 21 are further stabilized in the illustrated variants by means of Horizontal connections 25 are interconnected. The horizontal connections 25 can also be referred to as end beams. The crane 3 can be moved into the running gear 23, which is usually guided on rails. The crane beam 1 is moved in directions 7. Due to the inventive, at least partially outwardly bulging shape of the crane beam 1, its air resistance is significantly reduced, so that drive energy for moving the entire crane 3 including the crane beam 1 can be saved and less Drive power is required. In the illustrated embodiment, the crane girder 1 extends longitudinally in the longitudinal direction 27. In the portal cranes shown here, the direction of movement 7 is therefore orthogonal to the longitudinal extension 27. Fig. 2 shows an embodiment of a gantry crane with only one main girder, similar in basic construction to Fig. 1. Only the differences from Fig. 1 will be discussed here. Otherwise, what was said about Fig. 1 applies. The essential The difference between the embodiment shown in Fig. 1 and that shown in Fig. 2 lies in the fact that in Fig. 2 a bracing system known per se is provided by means of struts 16, on which the crane girder 1 is additionally suspended. This is advantageous when particularly heavy loads are to be attached to and transported on the trolley 15 and / or when, as shown here, the The crane girder 1 extends very far in the horizontal direction beyond the space between the supports 21, thus having a very large longitudinal extent in the longitudinal direction 27. In Fig. 3, the embodiment from Fig. 2 is further modified. Here, the crane girder 1 according to the invention has a crane girder section 24, which is additionally pivotable in the vertical direction shown by the double arrow 31. The drive for pivoting the crane girder section 24 in the directions according to the double arrow 31 is not shown here. However, it can be implemented in a manner known per se. In this embodiment according to Fig. 3, therefore, at least the crane girder section 24 of the crane girder 1 not only in the The crane girder 1 can be moved not only in direction 7 but also in the direction of movement according to double arrow 31. Nevertheless, the crane girder 1 is also designed in such a way that, when the crane 3 together with the crane girder 1 moves in direction 7, it leads to a corresponding reduction in air resistance and thus to... This leads to a reduction in the required drive power. However, Fig. 3 is also an example showing that a crane 3 according to the invention does not necessarily have to be a gantry crane. Rather, it is the Crane girder section 24 around a crane girder of a jib crane. The The embodiment shown in Fig. 3 is therefore a combination of a gantry crane and a boom crane. The invention can of course also be implemented in numerous other types of cranes, in particular bridge cranes and other boom cranes, without this needing to be explicitly described in further detail here. As mentioned, Fig. 4 shows the cross-section through the crane girder 1, which is used in the embodiments according to Figs. 1 to 3. The cross-section shown is depicted in a plane perpendicular to the respective longitudinal extent of the main girder 1. This also applies to the cross-sections according to Figs. 5 and 6, which will be explained below. In the embodiment shown in Fig. 4, the sections 10 and 11 forming the upper and lower chords are each provided with an outwardly bulging shape to reduce air resistance. In the operating position shown here, section 10 of the outer wall 6 points upwards and also ensures that rainwater or other precipitation, if it collects at all, can only collect in a very small area of ​​the crane girder 1 towards the rails or running surfaces 13. To allow this water to drain away, the main girder 1 can be slightly inclined in its longitudinal direction 27. In addition to reducing air resistance, the outwardly bulging shape of sections 10 and 11 also ensures high stability of the main girder 1, enabling it to absorb large static forces without the need for stiffeners or other reinforcements inside the cavity 5 enclosed by the outer wall 6. must be provided for. Furthermore, the outwardly bulging sections 10 and 11 also reduce the susceptibility of the crane girder 1 to generating noise through vibration excitation. The crane girder 1 is designed in the form of the hollow profile 4. The outer wall 6 encloses the cavity 5. In the illustrated embodiment, the outer wall 6 consists of the two sections 10 and 11 already mentioned, as well as the straight wall sections 12. In this embodiment, the straight wall sections 12 are designed as double T-beams, as are known from steel construction in general. They allow very large forces generated by the load of the trolley 15 to be absorbed via the running surface 13. In the embodiment according to Fig. 4, the outwardly bulging shapes of the outer wall 6, i.e., sections 10 and 11, are rounded. Both the width extent 17 and the thickness extent or height extent 18 are shown.The width extent 17 of the. The outer wall 16, viewed in a direction parallel to the direction of movement 7, is bounded at the first end 8 and at the second end 9. In the diagram shown here Viewed in cross-section through the crane girder, the orthogonal to the Direction of movement 7, measured distance 19 between each other Opposite sections of the outer wall 6 from both ends 8 and 9 of the width 17 of the cavity 5 towards the central area 20 of the cavity, at least partially. Some distances 19, which are to be measured orthogonally to the width 17, are shown as examples. The cross-section of this crane girder 1 has two axes of symmetry 28. One of them, namely the horizontal one, runs parallel to the direction of movement 7 and thus also parallel to the width 17. Fig. 5 shows a first alternative to the cross-section according to Fig. 4. Here, the two opposing upper and lower chords, i.e., sections 10 and 11 in the cross-section shown, are not rounded but polygonal in order to realize the outwardly bulging shape of the outer wall 6 according to the invention. Otherwise, what has been said about Fig. 4 applies. Fig. 6 shows a further variant in the form of a modification of Fig. 4. Here, a longitudinal groove 29 of the outer wall 6 is provided in the lower chord 11. Supply lines or the like can be guided in this groove. Nevertheless, it also applies here, at least in sections, that a groove perpendicular to the direction of movement 7 The measured distance 19 between opposing sections of the outer wall 6 increases from both ends 8 and 9 of the width extension 17 of the cavity 5 towards a central area 20 of the cavity 5. In the embodiments shown in Figs. 4 to 6, the cross-section through the main support is, at least in a first approximation, lens-shaped. Legend Regarding the reference numbers: Crane girder 31 double arrow crane Hollow profile cavity Exterior wall Direction of movement first end second ending Section Section straight wall section tread balance bike trolley strut Width Thickness extension Distance central area support yoke chassis Crane girder section Horizontal connection Horizontal connection Longitudinal direction axis of symmetry longitudinal groove

Claims

Patent claims Crane girder (1) for a crane (3), wherein the crane girder (1) has a hollow profile (4) with an outer wall (6) enclosing a cavity (5) and is elongated, and the outer wall (6) of the crane girder (1), viewed in a cross-section through the crane girder (1), has a shape that bulges outwards at least in some areas to reduce air resistance, wherein the outer wall (6), viewed in the cross-section through the crane girder (1), has two opposing sections (10, 11) with an outwards bulging shape, which are connected by means of two opposite straight wall sections (12) of the outer wall (6) are connected to each other, and the crane girder (1) has at least one running surface (13) for at least one running wheel (14) of a trolley (5) of a lifting device of the crane (3), characterized in that the opposite sections (10, 11) with outwardly bulging shape point upwards and downwards in an operating position of the crane girder and the straight wall sections (12) limit the crane girder (1) laterally in the operating position, wherein the wall sections (12) extend vertically and the running surface (13) is arranged and / or supported on, preferably on, one of the straight wall sections (12) of the outer wall (6). Crane girder (1) according to claim 1, characterized in that the crane girder (1) is movable in at least one direction of movement (7) and a The width (17) of the outer wall (6) of the crane girder (1) is bounded parallel to the direction of movement (7) by a first end (8) and a second end (9) of the width (17) of the outer wall (6) and, viewed in the cross-section through the crane girder (1), is orthogonal to the Direction of movement (7) measured distance (19) between opposing sections of the outer wall (6) from at least one of the ends (8, 9) of the width extension (17), preferably from both ends (8, 9) of the width extension (17), of the cavity (5) towards a central area (20) of the cavity (5) increases at least in certain areas.

3. Crane girder (1) according to claim 1 or 2, characterized in that the outer wall (6), which bulges outwards at least in some areas, is rounded in cross-section through the crane girder (1).

4. Crane girder (1) according to claim 1 or 2, characterized in that the outer wall (6), which bulges outwards at least in some areas, is polygonal in cross-section through the crane girder (1).

5. Crane girder (1) according to one of claims 1 to 4, characterized in that the running surface (13) is designed as a rail.

6. Crane girder (1) according to one of claims 1 to 5, characterized in that the crane girder (1) is movable in at least one direction of movement (7) and a width extent (17) of the outer wall (6) of the crane girder (1) parallel to the direction of movement (7) is greater or less than a The thickness extension (17) of the outer wall (6) of the crane girder (1) is orthogonal to the direction of movement (7).

7. Crane (3), in particular gantry crane or bridge crane or jib crane, characterized in that it has at least one crane support (1) according to one of claims 1 to 6.