Rolling Mill

The present invention relates to a rolling mill for rolling metal rods, wires or pipes along a rolling axis, comprising a plurality of stands which are arranged one behind the other along the rolling axis and are each received in a stand base, each of which comprises three rollers that are positioned on a roller shaft in each case and surround the rolling axis in a star-shaped manner, and which together form a caliber.

Rolling mills for rolling rod-shaped material to be rolled are known in principle in the production of metal pipes, rods, or wires. In this case, material to be rolled can be rolled to desired diameters, in that the caliber is set accordingly. A stand for a rolling mill of this kind is known for example from DE 100 15 340 A1.

In general, a plurality of stands is arranged in succession in a rolling mill. As a result, the material to be rolled can be stretched in particular by a difference between the roller speeds of the individual stands, and rolled to a smaller diameter.

Furthermore, the roundness of the material to be rolled is generally not sufficient after passing through one stand, because the cross-section assumes a polygon-like shape on account of the typically star-shaped arrangement of the rollers and their relatively small number, the number of sides of the polygon corresponding to the number of rollers of the stand. For example, a material to be rolled that is rolled by a single three-roller stand has a cross-sectional shape which is not ideally round but rather approximately triangular.

The successive stands are preferably arranged, for improving the roundness of the material to be rolled, in such a way that in each case the corners of the cross section, of a material to be rolled, of a material to be rolled that is leaving the stand, are contacted centrally by the rollers of the following stand, and the cross-section of the material to be rolled is rounded as a result.

Therefore, the three rollers in each case, for example of the first and third stand of a rolling mill having four stands, are typically located in what is known as a “Y-arrangement”, and the rollers of the stand arranged therebehind in each case, for example the second and fourth, are arranged in what is known as an “anti-Y-arrangement” (A). Due to the alternating arrangement of the rollers and stands in a Y-arrangement and anti-Y-arrangement, in each case the corners of the cross-section of the material to be rolled are rolled using the following stand, by a roller, and the cross-section of the material to be rolled is rounded as a result.

In the Y-arrangement, the lower roller is oriented in such a way that its roller shaft is positioned horizontally, i.e. the diameter of the lower roller extends vertically, in the viewing direction of the rolling axis. In contrast, in the anti-Y-arrangement it is the upper roller that has its roller shaft positioned horizontally, i.e. the diameter of the upper roller extends vertically, in the viewing direction of the rolling axis. In both cases, the roller shafts of the two further rollers are positioned tilted by 120° in each case, relative to the horizontal roller shaft. Of course, the arrangements relative to the horizontal are arbitrary overall, because it is only the relative arrangement of the rollers with respect to adjacent stands that is important for the effect described here.

The arrangement of the stands one behind the other to form a rolling mill typically takes place using stand bases, into which the stands are introduced and by which they are held. This makes it possible to replace stands from the rolling mill, for example for the maintenance which is regularly required.

The rollers are typically arranged on the roller shafts in a force-fitting manner and are driven by a drive of the roller shafts. For this purpose, there is the concept of driving each of the roller shafts separately by means of an independent drive, or driving a plurality of the roller shafts together, via a corresponding gearbox, by means of a single drive. The present invention relates to the concept of separate driving of the roller shafts by means of an individual drive in each case.

In the case of this concept, there is the difficulty that a very large amount of installation space is required in order to accommodate the plurality of drive motors and corresponding reduction gears. In this case, there is in particular the problem that the motors must be arranged at a significant distance from the rolling axis, in order to be at a sufficient spacing from one another.

Against this background, an object of the present invention is that of constructing a rolling mill for rolling metal rods, wires, or pipes along a rolling axis, which block is built in as space-saving a manner as possible. In particular, the object of the present invention is that of additionally also constructing the rolling mill in such a way that also the fewest possible resources are required for production and installation of the rolling mill, without having to compromise the performance of the rolling mill, in particular in the case of rolling performance during operation of the rolling mill.

This object is achieved by a rolling mill according to claim. Advantageous embodiments of the invention emerge from the dependent claims.

A preferred rolling mill for rolling metal rods, wires or pipes along a rolling axis comprises two or more stands which are arranged one behind the other along the rolling axis and are each received in a stand base. In this case, each of the three stands comprises three rollers that are positioned on a roller shaft in each case and surround the rolling axis in a star-shaped manner, and which together form a caliber. At least two of the three roller shafts of each of the stands are in each case operatively connected to a drive unit. Said drive unit comprises a motor having a motor shaft, and comprises a gearbox having a Z-shaped gearbox housing, having a drive shaft, which is preferably flush with the motor shaft and coupled thereto, and comprising an output shaft which is offset in parallel with the drive shaft and is preferably flush with the roller shaft and coupled thereto.

In this case, the drive unit of in each case at least one of the roller shafts of the stands is configured in a first configuration, in the first configuration a part of the drive shaft protruding out of the gearbox housing, or a part of the motor shaft and a part of the output shaft protruding out of the gearbox housing, or a part of the roller shaft, are in each case arranged so as to overlap axially with a part of the gearbox housing. In addition, the drive unit of in each case at least one other of the roller shafts of the stands is configured in a second configuration, in the second configuration a part of the drive shaft protruding out of the gearbox housing and the motor shaft and a part of the output shaft protruding out of the gearbox housing and the roller shaft are arranged so as to be without axial overlap with respect to the gearbox housing.

The gearboxes of the drive units in each case comprise the Z-shaped gearbox housing, which allows for an offset between the drive shaft and output shaft both radially with respect to the axis of the two parallel shafts, and also along the axis of the two parallel shafts.

Said Z-shaped design of the gearbox housing makes it possible to arrange the gearbox in different configurations, such that, depending on the requirements, a particularly small spacing between the motor shaft coupled to the drive shaft of the gearbox, and thus also to the motor itself, and the roller shaft coupled to the output shaft of the gearbox, and thus also the stand, can be achieved thereby. This is the case in the first configuration, in which an axially overlapping arrangement of the gearbox housing with the shafts coupled to the gearbox or the corresponding coupling parts of the drive and output shafts is provided. Due to the axial overlap, the gearbox is connected in such a way that, in the axial direction, viewed along the axis of the roller shafts and thus also of the motor shafts, it adds little, if anything, to the installation space requirement.

However, in the second configuration, the Z-shaped housing can also be arranged in such a way that the gearbox is arranged, in its axial extension, between the roller shaft and the motor shaft, and thus leads to a relatively large spacing between the motor shaft, and thus the motor, on the one hand, and the roller shaft, and thus the stand, on the other hand.

The fact that the output shafts are flush with the roller shafts makes this part of the torque gearbox unsusceptible for interference and allows a high degree of stability. A universal shaft and a non-flush alignment of the roller shafts and associated output shafts, and the motor shafts and associated drive shafts, is also possible, however.

Preferably, the third of the three roller shafts of each of the stands is also operatively connected to a drive unit of this kind, which drive unit comprises a motor having a motor shaft and a gearbox having a Z-shaped gearbox housing, and having a drive shaft which is flush with the motor shaft and is coupled thereto, and having an output shaft which is offset in parallel with the drive shaft and is coupled thereto. In this case, the drive unit is preferably configured in the first configuration or in the second configuration, as are defined and described above.

Preferably, the roller shafts of adjacent stands are oriented in parallel with one another and are arranged so as to be offset relative to one another, perpendicularly to the rolling axis. In this case, all drive units that are operatively connected to those of the roller shafts that are oriented in parallel with one another in each case are configured in the first configuration or in the second configuration.

In particular in the case of a change of adjacent stands between the Y-arrangement and the anti-Y-arrangement, the roller shafts can be arranged in a manner shifted in parallel, such that the roller positioned on the respective shaft rolls the material to be rolled alternately from opposite sides and in opposite directions. The fact that the drive units of parallel roller shafts are configured identically, i.e. in the first configuration or in the second configuration, leads to an efficient use of space. Furthermore, this makes it possible that, in the case of drive units arranged above the stand an overall relatively lower installation height is achieved over the entire rolling mill and not only a single stand, at the same high clearance height beside the stand. In the case of drive units arranged under the stands, a more uniform, relatively large spacing of the gearbox housing and motors from the stand housings is possible, such that peripheral devices, such as in particular a rail system for a stand-changing carriage, or other devices and machines that approach the stand laterally, have sufficient space. The same gearbox housing can be used for the two requirements, which are at first sight contradictory, and therefore the present rolling mill can be used very flexibly and can nonetheless be produced very cost-effectively in the process, due to the versatile use of the individual elements.

In this case, it is particularly preferable for the drive units of adjacent stands, operatively connected to the roller shafts that are oriented in parallel with one another in each case, to be oriented in such a way that the output shafts are offset alternately in opposite directions, relative to the drive shafts. Thus, the above-described efficient use of space can be achieved at the same time, and the motors of the drive units can be at a large spacing from one another, even close to the rolling axis, which makes it possible that the motors can be formed relatively large and can be arranged relatively close to the rolling axis.

Preferably, in each case a first of the three roller shafts of each of the stands is oriented in such a way that the drive unit, operatively connected thereto, is located above the stands. In this case, the drive units operatively connected to the first of the three roller shafts are configured in the first configuration, in order to allow for a small installation height of the rolling mill above the rolling axis, and in this case simultaneously to achieve a significant clearance height laterally to the rolling mill for a person or peripheral devices.

In this case, it is particularly advantageous for the motors of the drive units operatively connected to the first of the three roller shafts to be mounted on the gearbox housing of the respective drive unit by means of a bracket. Due to their Z-shape and the arrangement obliquely above the rolling mill, the gearbox housings make it possible for them not to require any additional crossbeams, on which they rest, but rather carry the gearbox, preferably also the associated motor, at least in part, themselves.

Gearbox housings can together form an unsupported bridge for arranging the gearboxes that are arranged side by side. In other words, they do not require their own steel crossbeams. At least some of the weight load of the respective motors can also be absorbed by the gearbox housings. Preferably, the motors can be held both by the gearbox housings and by one or more additional supports.

In a preferred embodiment, in each case a second of the three roller shafts of each of the stands is oriented in such a way that it is located with its operatively connected drive unit below the stand. In this case, the drive units operatively connected to the second of the three roller shafts are configured in the second configuration, in order to allow significant clearance under the stands for peripheral elements.

The peripheral elements can in particular be a rail system for a stand-changing carriage. The stand-changing carriage is a carriage for simultaneously changing a plurality of stands, e.g. for servicing or for quick adjustment to another material to be rolled. Therefore, the stand-changing carriage exerts a very high load on the ground, and therefore it is preferably moved on a rail system. Said rail system requires installation space in the ground, which can be favorably bridged with the arrangement of the drive units in the second configuration.

In the case of a preferred rolling mill, in each case a third of the three roller shafts of each of the stands is oriented horizontally, such that the drive unit operatively connected thereto is located beside the stands.

In this case, the drive units operatively connected to the third roller shafts can be configured in the second configuration, in order to allow a large spacing between the motors of the drive units of adjacent stands.

Alternatively, the drive units operatively connected to the third roller shafts can be configured in the first configuration, in order to allow a small amount of installation space beside the stands. Thus, depending on the installation situation, use can be made of the various advantages of the first and second configuration of the drive units. This emphasizes the large degree of flexibility which is achieved by the particular Z-shaped gearbox housing and the preferred arrangement and orientation of the drive units.

In a preferred embodiment, the gearbox housing comprises at least one intermediate shaft, in addition to the drive shaft and the output shaft. A particularly pronounced Z-shape of the gearbox housing can be achieved by the intermediate shaft, which shape makes it particularly easily possible for the gearbox housing to contribute, in the manner set out above, to a particularly flexibly configurable rolling mill.

The gearbox preferably comprises the intermediate shaft and a shifting shaft, in addition to the drive shaft and the output shaft.

The stand housing of the stand or all the stands of the rolling mill preferably has a hexagonal external shape, viewed along the rolling axis. As a result, the stand can be easily received in the stand base in the Y-arrangement and anti-Y-arrangement, the drive units, the positions and orientations of which have to follow the positions and orientations of the roller shafts, being able to be arranged in a particularly favorable manner. This applies in particular for further peripheral devices, such as a remote adjustment means for the rollers, the arrangement and orientation of which can be maintained or largely maintained, if the hexagonal external shape of the stands for different arrangements and configurations of the stands is selected skillfully.

Further advantages and developments of the invention emerge from the following description of the figures, and all of the claims.

is a schematic view of a preferred rolling mill, including drive units.,.,., viewed along a rolling axis. The rolling axis thus extends perpendicularly to the image plane, in the view in this figure.

In the center of the figure, a standis shown which comprises a stand housinghaving a hexagonal external shape. The external shape represents a regular hexagon, the standbeing positioned on a horizontally oriented side of the hexagon. The standcomprises three rollers.,.,.which each define a rolling plane in which the periphery of the roller.,.,.extends. Each of the rollers.,.,.is positioned on a roller shaft.,.,.extending mainly perpendicularly to the rolling plane. The rollers.,.,.surround the rolling axis in a star-shaped manner, and in the process form a caliberthrough which the material to be rolled is guided during rolling.

The star-shaped arrangement of the rollers.,.,.is shown inin what is known as the anti-Y-arrangement. This designation is derived from the fact that the rolling planes of the rollers.,.,.are located as a vertical plane above the caliber, and two planes that are in each case inclined at a 120° angle to the vertical plane, which, in the viewing direction along the rolling axis, resembles an inverted letter Y. In contrast, the standshown inis shown in what is known as the Y-arrangement, because here the vertical rolling plane is located under the caliberand the arrangement of the rolling planes, viewed along the rolling axis, thus resembles a letter Y.

The standvisible in, and the standsthat are arranged flush one behind the other along the rolling axis, and are thus hidden in, are each received in a stand base, which surround the relevant standin part, from the left in the perspective view of. A lower edge, a side edge, and an upper edge of the standare received by the stand base. In this case, four of the six side surfaces.,.,.,.,.,.of the regular hexagon described by the external shape of the respective stand, which surfaces are side-by-side, are surrounded by the associated stand base.

The rollers.,.,.are attached to the roller shafts.,.,.without clearance, for example are pushed or shrunk onto the roller shafts.,.,.in a force-fitting manner, and are driven by driving the roller shafts.,.,.. In order to drive the roller shafts.,.,., the rolling millis provided with drive units.,...

Each of the drive units.,.,.drives a roller shaft.,.,., and thus a roller.,.,.. For this purpose, each drive unit.,.,.comprises a motor.,.,.having a motor shaft and a gearbox.,.,.having a Z-shaped gearbox housing.,.,., a drive shaft.,.,.that is flush with the motor shaft and is coupled thereto, and an output shaft.,.,.that is offset in parallel with the drive shaft.,.,.and is flush with the roller shaft.,.,.and coupled thereto.

A coupling.,.,.is located on the stand, via which coupling the output shaft.,.,.of the drive unit.,.,.can be coupled to the roller shaft.,.,.. In this case, it is also possible for the roller shaft.,.,.or the output shaft.,.,.to be composed of a plurality of partial shafts. The fact that the output shaft.,.,.is flush with the roller shaft.,.,.makes this part of the torque gearbox unsusceptible for interference and increases the stability. It is also conceivable, however, to provide a universal shaft.

In the embodiment shown in, the output shaft.,.,.is formed in two parts and comprises a first part which extends between the standcomprising the coupling.,.,.of the roller shaft.,.,., and the Z-shaped gearbox housing.,.,.. Furthermore, the output shaft.,.,.comprises a second part, which extends from the first part of the output shaft.,.,.into the gearbox housing.,.,..

Corresponding to the number of three roller shafts.,.,., per stand, three drive units.,.,.are in each case arranged, with a roller shaft.,.,., flush around the stand. In this case, in the perspective view in, per standa first drive unit.is arranged at the top right, a second drive unit.at the bottom right, and a third drive unit.at approximately the same height, to the left of the stand.

The first drive units.are configured in a first configuration. In this configuration, the second part of the output shaft.extends at least in part next to one part of the gearbox housing., before it enters the gearbox housing.. The output shaft.thus enters a part of the gearbox housing.that is located set back from the rolling axis, and thus extends in a manner axially overlapping with a part of the gearbox housing., at least in part. This configuration of the Z-shaped gearbox housing.results in an offset between the output shaft.and the drive shaft., such that the spacing between the motor.of the first drive unit., and the rolling axis, is small. Due to the offset, in the first configuration the gearbox housing.reduces the spacing between the motor.of the drive unit.and the standor the rolling axis.

The second drive units.are configured in a second configuration. In this configuration, the second part of the output shaft.does not extend beside the gearbox housing.before it enters the gearbox housing.. In this respect, the second configuration is an opposite orientation of the Z-shape of the gearbox housing., such that the spacing between the motor.of the second drive unit.and the rolling axis is large. Due to the offset, in the second configuration the gearbox housing.increases the spacing between the motor.of the drive unit., and the standor the rolling axis.

While the Z-shape of the gearbox housing.of the second drive units.means that a compact structure is assumed, i.e. the motors of the second drive units.are arranged relatively close to the rolling axis and the stand, when the first part of the output shaft.is the same length as in the second configuration, the Z-shape of the gearbox housing.of the second drive units.results in a space-consuming structure, in which the motors.of the second drive units.are arranged relatively far away from the rolling axis and the stand, when the first part of the output shaft.is the same length as in the first configuration.

In the case of the second drive units., a large spacing is advantageous, because in this way an installation space of a rail systemfor a stand-changing carriage, in the ground, can be favorably bridged, without extending the shafts and thus increasing a dynamic instability. In the case of the first drive units., a small spacing is advantageous, because in this way an installation height of the rolling mill, upwards, can be kept small.

Like those of the second drive units., in the embodiment shown inthe gearbox housings.of the third drive units.are configured in the second configuration, such that the spacing between the motors.of the third drive units.and the respective standsand the rolling axis is extended by the gearbox housing., when the output shaft.is the same length.

The first configuration of the Z-shaped gearbox housing.,.,., having an axially overlapping arrangement of a part of the output shaft.,.,.and of the gearbox housing., and the second configuration of the Z-shaped gearbox housing.,.,., having a non-overlapping, i.e. overlap-free, arrangement of the output shaft.,.,.and the gearbox housing.,.,., result in the gearbox housing.,.,.either leading to an increase in the spacing between the respective motor.,.and the stand, or the extension of the gearbox housing..,.along the orientation of the roller shaft.,.,.is virtually or completely compensated by the Z-shape.

In addition, the orientations of the first and second drive units.,.of successive stands, i.e. standslocated one behind the other along the rolling axis, differ from those of the third drive units..