Rack replacement bracket

Abstract

The invention relates to a stand exchange carriage (10) for simultaneously receiving and transporting a plurality of stands of a rolling mill for rolling metal bars, wires or pipes, the stand exchange carriage (10) comprising a plurality of stand seats (16), one of the stands being individually receivable in each of the stand seats (16), the stand change carriage (10) comprises a plurality of steerable wheels (20) for transporting the stand on a guide rail or along a guide-less rolling mill floor, and comprises at least one hydraulic motor (21) operatively connected to at least one of the wheels (20) for driving the wheels.

Description

Technical Field

[0001] The present invention relates to a frame changer for simultaneously receiving and conveying multiple frames of a rolling mill used for rolling metal rods, wires or pipes. Background Technology

[0002] To roll metal rods, wires, or pipes, a rolling mill is typically used, which includes multiple stands arranged one after another in the rolling direction. Each stand contains actual rollers that apply rolling forces to the material to be rolled, thereby forming the metal rod, wire, or pipe from the material.

[0003] During operation, the rollers wear down and therefore must be overhauled at regular intervals. For this purpose, the stand containing the roller to be overhauled must be removed from the rolling mill and transported to the stand shop. After the roller is overhauled, the corresponding stand must then be transported back from the stand shop to the rolling mill and inserted into it. Furthermore, different stands are required for rolled products of different thicknesses, and the diameter of the stands is preset to the desired thickness of the corresponding rolled product.

[0004] For the exchange of stands in a rolling mill, a stand changer is used in a known manner, which can simultaneously accommodate multiple stands and reliably transport stands between the rolling mill and the stand shop. As described, for example, in DE 102014015 963A1, in this case, in principle, a distinction can be made between two different types of stand change systems in which different stand changers are used.

[0005] In well-known first-stand changing systems, the stand changing carriage does not have its own drive mechanism but is moved by means of one or more external control cable systems. For this purpose, the control cables and the traveling trolleys secured thereto are routed under the mill base plate, forming a base on which the wheels of the stand changing carriage travel. The changing carriage can be attached to the traveling trolley by means of a coupling rod and can be moved via the control cables. In this system, the stand changing carriage is rail-mounted, and it is known that in addition to a first rail extension parallel to the mill extension, a second rail extension perpendicular to the mill positioning is also provided. At a switch connecting the two extensions, the stand changing carriage can be switched between the extensions by rotating the wheel pivot approximately 90°. Therefore, for example, if the stand changing carriage is temporarily parked on the transverse rail, the sequence of stand changing carriages in front of the mill can be changed. In this system, the choice of which stand changing carriage should be returned to the stand shop or moved to the mill is relatively flexible.

[0006] Because the stand-changing brackets in this type of setup do not have any drive shafts, the control cable system recessed into the mill floor allows for a lower assembly height for the stand-changing brackets. Specifically, wheels that can pivot approximately 90° can also be easily implemented. However, this comes at the cost of increased space requirements under the mill floor, as several necessary components of the control cable system (e.g., coupling and decoupling stations, cable tensioners, and switch actuators) must be accommodated there. This is particularly disadvantageous when the mill is located above the mill level, as the ceiling height of the lower level must be significantly reduced in the area of ​​the control cable system, leading to structural technical complexity. Furthermore, in this concept, the complexity of the control cable system increases very rapidly with the number of stand-changing brackets to be moved and the extension of the guide rails, and it is less adaptable to structural changes within the mill or stand shop.

[0007] In the second type of stand-changing system, the stand-changing carriage has a direct electric drive with one or more wheels. Stand-changing systems including such carriages are theoretically more scalable because the control cable system in the rolling mill can be omitted. However, the power supply lines are still connected to these "self-propelled devices" with cable carriers to ensure the necessary control signals and power supply to the electric motors. Due to the cable carriers, these stand-changing carriages are also used only for cable installation, with only one cable carrier per rail extension, and therefore only one carriage has its own drive. Furthermore, the need for very long lines makes it practically difficult to move the stand-changing carriages directly to a remote stand shop. Therefore, the removed stands must be carefully and time-consumingly reloaded from the stand-changing carriages onto different transport components already near the rolling mill, where space is typically limited due to other structural reasons.

[0008] Furthermore, in practice, only those second-type stand-changing trays are used, which can only move forward and backward, but not laterally. Therefore, the stand-changing tray cannot be changed along the rolling mill sequence, and it is impossible to park this type of stand-changing tray in the second row in front of the rolling mill until the second row is used. The reason why there are no electrically driven stand-changing trays that can change their direction of travel is due to the available installation space. Due to the sufficiently large size of the electric motor and its drive unit, the wheel arches of the second type of stand-changing tray require more space compared to the first type. Nevertheless, in order to design the stand-changing tray as compact as possible overall, the wheels are therefore placed in the intermediate space provided between the stand seats. However, it is no longer possible to position an electrically driven device with helical gears in this limited space, which can pivot with the wheels to thus allow for immediate changes in direction of travel. In other words, the space requirement for the wheel arches of the stand-changing tray would be too large. A lateral clearance must also be provided around the stand-changing bracket, into which the drive unit, consisting of an electric motor and gearbox, can extend when the wheels are pivoted. However, a distance that is too large between the stand-changing bracket and the rolling mill is disadvantageous when the stand is inserted into the rolling mill. Another reason is the need for electrical supply lines. As in control cable systems, after transferring to another rail extension, the stand-changing bracket must be immediately connected to a different cable carrier, which is associated with additional technical complexity. Furthermore, it must be ensured that the cable carriers of individual rail extensions are not damaged when crossing the stand-changing bracket. Summary of the Invention

[0009] In this context, an object of the present invention is to provide a rack changer with a drive concept in the aforementioned technical field, which is more flexible in use than those in the prior art. Specifically, an object of the present invention is to provide a rack changer whose direction of travel can be changed. Specifically, an object of the present invention is to provide a rack changer that can be used in as many different workshops as possible in a multifunctional manner. Specifically, an object of the present invention is to provide a rack changer that can be used as autonomously as possible.

[0010] This objective is achieved by replacing the rack bracket according to technical solution 1. Advantageous embodiments of the invention are described in the accompanying technical solutions.

[0011] A stand changing bracket for simultaneously receiving and conveying multiple stands of a rolling mill used for rolling metal rods, wires, or pipes includes: multiple stand seats, one of which can be individually received in each of the stand seats; and multiple steering wheels for conveying the stand along a guide rail or a guide railless mill base plate.

[0012] The rack changing bracket includes at least one hydraulic motor operatively connected to at least one of the wheels to drive the wheel.

[0013] Hydraulic motors are characterized by their high drive torque. Therefore, specifically, they are suitable for moving heavy-duty racks to change carriages. Furthermore, compared to electric motors with similar torque, hydraulic motors offer a more compact design. Thus, the use of hydraulic motors makes it possible to keep the wheel arch size relatively small. For example, if pivoting of the wheel is possible via a bevel gear mounted on the wheel, then the space requirement for the wheel arch, despite the additional components, will not increase further compared to a non-pivotable wheel driven by an electric motor.

[0014] Furthermore, the compact space requirement of the hydraulic motor allows the mounting height of the stand changer according to the invention above the mill base plate to be comparable to that of known stand changer brackets driven by control cables. Therefore, the present invention has the potential to provide a steerable and self-propelled stand changer. Consequently, the stand changer is independent of external drive mechanisms and guide rail systems, and thus can be used in more functional ways than stand changer brackets known in the prior art.

[0015] In an advantageous embodiment, the hydraulic motor is a radial piston motor or an axial piston motor. These motor types, and especially radial piston motors, have a particularly compact design and allow for a particularly low mounting height of the steerable rack change bracket. Specifically, low-speed radial piston motors have a very compact design and, particularly, a very small extension in the longitudinal direction. This extension is preferably less than 0.2 m. In view of this, the longitudinal direction refers to the direction extending along the axis of rotation of the radial piston motor. If such a motor is used, the pivotable drive unit can be implemented by a hydraulic motor and wheels, requiring small wheel arches and a small clearance around the rack bracket for pivoting.

[0016] Preferably, each of the wheels is associated with and operatively connected to one of its own at least one hydraulic motor. For compact design purposes, it is possible to provide a separate hydraulic motor for each wheel. This, in turn, multiplies the driving force on the rack-changing bracket. It is also conceivable to replace a single large motor with relatively large space requirements, making a minimum mounting height of the rack-changing bracket necessary, with multiple smaller hydraulic motors having the same overall driving force; each of these hydraulic motors has a small space requirement. Therefore, the minimum mounting height can be reduced. Due to the small size of the hydraulic motors, specifically radial piston motors, in this preferred embodiment, it is possible to make each of the drive wheels steerable without requiring a large space. However, another option is that not each of the wheels may have its own hydraulic motor.

[0017] Preferably, all of the wheels are designed to be steerable, allowing for changes in the direction of travel of at least 30° or more, and more preferably 90° or more. A stand-changing bracket including such wheels can not only move in forward and backward directions, but can also immediately take a different direction, specifically perpendicular to the original direction of travel. As a result, the stand-changing bracket can be operated in a particularly simple and space-saving manner, and can also be operated in very tight environments. Therefore, multiple stand-changing brackets can be positioned in front of the rolling mill in any desired arrangement within a very tight space. However, another option is that only some of the wheels may be steerable, or steerable around a smaller steering angle. Therefore, the alignment of the stand-changing bracket with the rolling mill can be set.

[0018] In this configuration, the contact surface of the stand base, where the stand remains after being received in the stand changing bracket, is spaced 50 cm or less from the mill base plate, preferably 40 cm or less, more preferably 30 cm or less, and even more preferably 20 cm or less. In this way, in the case of a conventional stand, it is possible to ensure that the lowest point of the stand is positioned just above the mill base plate. However, another option is that, for transporting the stand at a lower height, the mill base plate may also be recessed, or the stand may be lifted to a higher contact surface by means of a crane, etc., and transported at this height.

[0019] In conventional bar rolling mills, the rolling line extends approximately 0.9m to 1.1m above the mill base plate, and sometimes even lower. Therefore, the lower side of the stand is typically located only approximately 0.2m to 0.3m above the mill base plate. Thus, in the area where the stand is received, it is desirable that the mounting height of the replacement bracket not be higher. According to this preferred feature, since the contact surface of the stand, after being received in the stand replacement bracket, is spaced 40cm or less from the mill base plate, the stand replacement bracket can be advantageously used in existing rolling mills without requiring strenuous adjustments to the rolling mill or mill base plate. In some cases, the lowest point of the stand is a downwardly projecting coupling portion. This coupling portion defines the lowest point. According to the aforementioned advantageous feature, the stand replacement bracket is designed such that the coupling portion is located at a small, safe distance from the ground. However, not all rack designs have the downward-protruding coupling, and therefore, for these racks, a lower contact surface is possible than in the case of racks with this type of downward-protruding coupling. A lower contact surface is advantageous, particularly if the aim is to replace a control cable-based rack changing system, and where, due to structural constraints, the height of the rolling mill above the mill base plate is small. However, another option is that the contact surface of the rack where it is placed can also be designed to be higher.

[0020] Preferably, the rack changing bracket includes a steering drive to steer at least two, preferably all, of the wheels. This type of rack changing bracket can be rail-mounted or operated without rails. Therefore, in the case of rail-less operation, it is possible to manipulate the rack changing bracket and fix its direction of travel by corresponding positioning of the steering drive. In the case of rail-mounted rack changing brackets, the steering drive is advantageous because the switch between the two rail extensions no longer needs its own switch actuator to cause the wheels to turn. However, the wheels of the rack changing bracket can also be passively steered without a steering drive, for example, via rails.

[0021] Preferably, the steering drive includes a chain drive. In this way, the central input for the steering drive can be easily assigned to each steerable wheel of the rack changer. However, another option is that the steering drive can also be designed differently – specifically, multiple drives can be provided, each of which steers one wheel.

[0022] More preferably, the steering drive includes a spindle. The spindle can be incorporated into a chain drive. The spindle ensures that the steering drive can self-lock.

[0023] In an advantageous embodiment, the at least one hydraulic motor, together with its associated wheel, is deflectable about a steering axis. Thus, the motor and the wheel form a steerable drive unit. A ring gear is non-rotatably mounted on the drive unit, and the ring gear (e.g., the gear of the steering drive device) can engage with the drive unit to form a gearbox. In this way, the wheel can be steered immediately without applying a large force.

[0024] Preferably, viewed from above, during operation of the stand changing bracket, one of the stand seats is positioned between at least two of the wheels. As a result, the mounting height of the stand changing bracket in the area of ​​the stand seat can be kept particularly low, since the mounting height is not limited by the space requirements of the wheel arches. Therefore, it is possible to move the stand from the very low stand base of the rolling mill to the stand seat of the stand changing bracket without needing to overcome a significant height difference.

[0025] Preferably, the rack changing tray includes an energy source, specifically a battery, to supply power to the at least one hydraulic motor. This configuration allows the rack changing tray to operate independently of an external energy source. Therefore, cable trays for supply lines, specifically for cables, etc., can be completely omitted from the rack changing tray, and the rack changing tray is thus unrestricted in its radius of movement. However, an external energy supply is also possible in principle.

[0026] Advantageously, the at least one hydraulic motor is part of a closed hydraulic circuit including a pump, which is preferably designed without a tank. If the hydraulic motor is present in the closed circuit including the pump, pressure can be applied to the hydraulic fluid circulating within the closed system in the hydraulic circuit to operate the hydraulic motor. Then, for example, it is unnecessary to have a pressure vessel on the rack changing bracket that must be continuously pressurized from the outside. Therefore, a self-operating rack changing bracket can be achieved. Omitting the tank allows for a particularly compact design. However, providing a tank is also advantageous.

[0027] Preferably, a battery-operated electric motor is mounted on the rack changer bracket to supply hydraulic pressure to and thus drive the at least one hydraulic motor. This particularly preferred embodiment constitutes a powerful, emission-free, and autonomous variant of the rack changer bracket. In this configuration, the electric motor can be mounted at a point on the rack changer bracket that does not compromise the mounting height of the rack mount. The same applies to the battery.

[0028] Preferably, the rack changing tray is equipped with an inductive charging mechanism. If a rechargeable battery is used as an energy carrier to power its electrical components, then the battery can therefore be charged in a contactless manner. For example, it is conceivable to operate a rack changing tray equipped in this manner in a charging zone of the rolling mill or the rack workshop, in which the mating parts of the inductive charging mechanism are present in or on the ground when the rack changing tray is to be charged. This charging zone can also be set directly on the rolling mill to accommodate points with particularly high energy demands and relatively long dwell times. As a result, the battery can be small in size.

[0029] The stand-changing tray preferably includes a wireless data gearbox device for controlling the stand-changing tray. As a result, commands and parameters for its operation can be transmitted from an external control system to the stand-changing tray. For example, it is conceivable that the stand-changing tray can be remotely controlled and moved as needed between different locations in the rolling mill, in the stand shop, and / or between the rolling mill and the stand shop. In this case, control can be fully or partially autonomous. For example, it is conceivable that during automation, when the monitoring system identifies a stand change or finds a change necessary, a stand-changing tray can be provided in the stand shop or the rolling mill.

[0030] More preferably, the data gearbox device is configured such that it preferably transmits one or more operational states of the rack-changing tray to the control system and / or other rack-changing trays. Not limited thereto, the operational states may include battery charging status, rack loading status, and the position of the rack-changing tray. This allows the rack-changing tray to operate fully autonomously as a “self-guided guided vehicle” or “autonomous motion robot.” Therefore, multiple rack-changing trays can exchange their operational states directly and / or indirectly via the control system so that these states can also be taken into account during control.

[0031] Preferably, the rack replacement bracket includes at least four rack seats.

[0032] Therefore, many rolling mills are designed to include four stands arranged one after the other along the rolling direction. It is particularly advantageous to also provide four stand mounts for the stand changing brackets, so that, in the case of such stand mounts, all the stands can be exchanged simultaneously using the stand changing brackets.

[0033] Preferably, the rack base is designed to receive a rack having a hexagonal external shape when viewed along the rolling direction of the rack. However, alternatively, the rack base may also be designed to receive racks of different shapes, such as conventional racks with a square external shape.

[0034] Specifically in the case of a hexagonal stand, but also in principle in the case of a square stand, the coupling portion of the roller shaft (through which the rolling torque is introduced to the roller shaft) extends obliquely downwards and extends to the side of the stand from which it is exchanged. With this arrangement, the stand changing bracket described above can make an additional contribution to machine safety because if the stand changing bracket remains in the stand base during operation of the rolling mill, then the stand changing bracket covers these coupling portions during the operation of the rolling mill.

[0035] Further advantages and developments of the present invention are described in the following figures and in all claims. Attached Figure Description

[0036] Figure 1 This is a perspective side view of the preferred rack replacement bracket.

[0037] Figure 2 Showing from the opposite side Figure 1 The preferred rack replacement bracket.

[0038] Figure 3 The preferred rack replacement bracket is shown above.

[0039] Figure 4 The preferred rack replacement bracket is shown below.

[0040] Figure 5 This is a side view of a preferred rack replacement bracket where a rack seat is occupied by a rack. Detailed Implementation

[0041] Figure 1 A preferred rack changer 10 for accommodating four racks is shown. For this purpose, the rack changer 10 is equipped with four rack mounts 16 designed to individually accommodate one rack. Figure 1The view shows one side of the stand replacement bracket facing the rolling mill during stand replacement. Each of the stand bases 16 includes a recess 18 in the body 11 of the stand replacement bracket 10 and a sliding guide 17 on either side of the recess 18 in each case. On the sliding guide 17, the corresponding stand can be pushed into or lifted onto the stand replacement bracket 10. This pair of sliding guides 17 thus forms a contact surface for the stand housing receiving the stand, and the recess 18 provides space for portions of the stand protruding from the stand housing (e.g., coupling portions of rolling shafts). Between the stand bases 16, the stand replacement bracket 10 in each case includes (i.e., three in total) intermediate spaces 28. As will be further described below, additional components (in particular wheels 20) are arranged in the intermediate spaces 28 on the underside of the stand replacement bracket 10. On the upper side, the outer intermediate space 28 further accommodates the components of the steering drive unit under the cover 27, as will be explained in more detail below.

[0042] Figure 2 The rack changer 10 is shown from its opposite side. The recess 18 closes towards this side, ensuring a substantially uniform mounting height for the rack changer 10, except for the structures on the central space 28 and in its rear and front regions. In this embodiment, a hydraulic pump 32, driven by an electric motor 33, is attached to one side. In principle, the hydraulic pump 32 and / or the electric motor 33 could be accommodated at other points on the rack changer 10. However, attachment on the shown side is advantageous because these components do not obstruct access when approaching the rolling mill. The hydraulic pump 32 supplies pressurized hydraulic fluid to the hydraulic system of the rack changer 10.

[0043] In addition, a chain drive 22 is provided to one side. The chain drive 22 is part of the steering system, which will be described in more detail below, and is used to distribute the central input of the steering drive to all the steerable wheels of the rack change carriage.

[0044] Figure 3 The rack replacement bracket 10 is shown from above. In this view, the covers 27 above the two external intermediate spaces 28 have been removed. Therefore, the view of the spindle rod 25 is free, and the rod is arranged in the intermediate space 28 in each case. The spindle rod 25 includes a spindle 26 divided into two parts. A sprocket 34 is non-rotatably mounted on the spindle rod 25 facing the chain drive 22, into which the chain drive 22 engages. In each case, the spindle 26 meshes with an upper gear 29, which in turn drives a shaft 31 positioned perpendicular to the plane of the drawing.

[0045] Figure 4The rack changer 10 is shown below. In this view, the recess 18 is now the protrusion of the body 11 of the rack changer 10. Sufficient space exists in the intermediate space 28 to provide drive units 24, which in each case include a wheel 20 and a hydraulic motor 21. The hydraulic motor 21 is incorporated into the hydraulic system of the rack changer 10 in a manner conventional in the art. For clarity, the necessary hydraulic wiring is not shown. In general, the rack changer 10 comprises four structurally identical drive units 24, with two drive units sharing one of the intermediate spaces 28 in each case. In this embodiment, the hydraulic motor 21 of the drive unit 24 is designed as a radial piston motor, with a longitudinal dimension of less than 20 cm. Therefore, the drive unit 24 is very compact overall. Furthermore, a ring gear 23 is mounted on the drive unit 24. Each drive unit 24 can rotate together with its ring gear 23 about a steering axis perpendicular to the plane of the drawing. Due to its compact design, the drive unit 24 can rotate approximately 360° around the steering axis, and despite the small intermediate space 28, the drive unit will not collide with the main body 11 of the rack changer 10. Therefore, the direction of travel for each wheel 20 can be set as needed, resulting in the rack changer 10 being able to immediately execute any desired change in direction of travel. Figure 3 In the position shown, all wheels 20 are perpendicular to the longitudinal direction of the rack changing carriage, along which the rack is arranged. In the position shown, the rack changing carriage can therefore move from one side toward the rolling mill. Lower gears 30 mesh with the ring gears 23 of each drive unit, such that the corresponding drive unit 24 rotates about its steering axis by rotation of the lower gears 30. Thus, a total of four such lower gears 30 are provided, which are part of the steering drive mechanism of the rack changing carriage 10. Each lower gear 30 is connected via a shaft 31 to an associated upper gear 29, and thus to the chain drive 22. The mechanism is adapted to cause the wheels 20 to turn synchronously in the aligned direction during operation of the chain drive 22. However, embodiments are also contemplated in which another alternative is that, in each case, only two wheels 20 sharing the intermediate space 28 or arranged on one side of the rack changing carriage 10 can turn independently of the other two wheels 20. Thus, for example, the rack changing carriage 10 can be rotated in an efficient manner. Preferably, for this purpose, the rotation directions of the individual hydraulic motors can also be set differently from each other. The chain drive device 22 can be hydraulically driven, and for this purpose, the chain drive device 22 is incorporated into the hydraulic system, but it is also possible to use an electric motor for driving.

[0046] A battery 35 or battery pack is arranged in the central intermediate space 28, supplying power to the electric motor 33 and other components. The illustrated rack replacement bracket 10 can therefore move completely autonomously.

[0047] Figure 5 Showing the preferred stand change bracket 10 for stand replacement in the case of stand changing from the side facing the rolling mill, the stand 13 is received on the left-hand side stand base 16 in the viewing direction. Clearly, the coupling portion 15 of the stand 13, protruding from the stand housing 14, finds space in the recess 18 of the stand base 16. In this view, the mill base plate H, including the embedded guide rail S, on which the wheels 20 of the stand change bracket roll. In this embodiment, the mounting height B of the stand base 16 (i.e., the distance between the contact surface of the stand base 16 and the mill base plate H) is 39 cm.

[0048] Component Symbol List

[0049] 10. Replacement bracket for rack

[0050] 11 Main Body

[0051] 13 racks

[0052] 14. Rack housing

[0053] 15. Coupling section

[0054] 16 rack base

[0055] 17 Sliding guide rail

[0056] 18. Depression

[0057] 20 rounds

[0058] 21 Hydraulic motor

[0059] 22 Chain drive device

[0060] 23 Ring gear

[0061] 24 drive units

[0062] 25 mandrel

[0063] 26 mandrels

[0064] 27 Cover

[0065] 28. Intermediate Space

[0066] 29 Upper gear

[0067] 30 Lower gear

[0068] 31 Shaft

[0069] 32 Hydraulic pump

[0070] 33 Electric motor

[0071] 34 sprockets

[0072] 35 batteries

[0073] H Rolling Mill Bottom Plate

[0074] S-rail

[0075] B. Assembly height.

Claims

1. A stand changing bracket (10) for simultaneously receiving and conveying multiple stands (13) of a rolling mill used for rolling metal rods, wires, or pipes. The rack replacement bracket (10) includes a plurality of rack seats (16), wherein one of the racks (13) is individually accommodated in each of the rack seats (16). The stand changing bracket (10) includes a plurality of steerable wheels (20) for conveying the stand (13) on a guide rail (S) or along a guideless mill base plate (H). The rack changing bracket includes at least one hydraulic motor (21) operatively connected to at least one of the wheels (20) to drive the wheel.

2. The rack replacement bracket (10) according to claim 1, The hydraulic motor (21) mentioned therein is a radial piston motor or an axial piston motor.

3. The rack replacement bracket (10) according to claim 1 or claim 2, Each of the wheels (20) is associated with and thus operatively connected to its own at least one hydraulic motor (21).

4. The rack replacement bracket (10) according to claim 1 or 2, At least two, preferably all, of the wheels (20) are steerable in order to perform a change of travel direction of at least 30° or greater, preferably 90° or greater.

5. The rack replacement bracket (10) according to claim 1 or 2, The contact surface of the frame base (16) has an assembly height (B) of 50 cm or less, preferably 40 cm or less, above the mill base plate (H).

6. The rack replacement bracket (10) according to claim 1 or 2, The rack changing bracket (10) includes a steering drive to steer at least two, preferably all, of the wheels (20). The steering drive device preferably includes a chain drive device (22).

7. The rack replacement bracket according to claim 6, The at least one hydraulic motor (21) together with its associated wheel (20) forms a drive unit (24), the drive unit being pivotable about a steering axis, and a ring gear (23) being non-rotatably mounted on the drive unit.

8. The rack replacement bracket (10) according to claim 1 or 2, Viewed from above, at least one of the frame seats (16) is positioned between at least two of the wheels (20) during operation of the frame changing bracket (10).

9. The rack replacement bracket (10) according to claim 1 or 2, The rack replacement bracket (10) includes an energy source, specifically a battery (35), for supplying energy to the at least one hydraulic motor (21).

10. The rack replacement bracket (10) according to claim 1 or 2, The at least one hydraulic motor (21) is part of a closed hydraulic circuit including a pump (32). The hydraulic circuit is preferably designed to be without a storage tank.

11. The rack replacement bracket (10) according to claim 1 or 2, The battery-operated electric motor (33) is mounted on the rack changing bracket (10) to supply hydraulic pressure to the at least one hydraulic motor (21) and thus drive the motor.

12. The rack replacement bracket (10) according to claim 1 or 2, The rack replacement bracket is equipped with an inductive charging mechanism.

13. The rack replacement bracket (10) according to claim 1 or 2, The rack changer includes a wireless data gearbox device for controlling the rack changer (10), wherein the data gearbox device is preferably further configured to transmit the operating status of the rack changer (10).

14. The rack replacement bracket (10) according to claim 1 or 2, The rack replacement bracket (10) mentioned therein includes at least four rack mounts (16).

15. The rack replacement bracket (10) according to claim 1 or 2, The frame base (16) is designed to receive the frame (13), which has a hexagonal external shape when viewed along the rolling direction of the frame (13).

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