Reel and method for winding or unwinding strip-shaped material - Patents.com

Abstract

The present invention relates to a reel (10) for winding or unwinding a material in strip form, in particular a metal strip or the like, and to a method for drawing a coil (12), the reel comprising a frame (13), at least one reel head (14) on which the coil for winding or unwinding the material (11) is arranged, a drive (15) having at least one electric motor (16), and a shaft (20) connecting the electric motor and the reel head, the electric motor being formed with a stator (17) and a rotor (18) and arranged on the frame, the electric motor being a torque motor or a synchronous motor, the shaft connecting the rotor directly to the reel head and the rotor being mounted on the stator so as to be axially movable relative to the stator.

Description

[Technical field]

[0001] The present invention relates to a reel for winding or unwinding a material in strip form, in particular a metal strip, and a method for tensioning the coil, the reel comprising a frame, at least one reel head on which the coil for winding or unwinding the material is arranged, a drive having at least one electric motor, and a shaft connecting the electric motor to the reel head, the electric motor being formed with a stator and a rotor and arranged on the frame. [Background technology]

[0002] Reels of the above mentioned type are used, for example, in the production of strip in a rolling process, where the strip is generally unwound from a first reel with a defined strip tension, in a one-way or reversing operation, moved through the roll gap of the rolling device and wound on an additional reel with a defined strip tension. In a subsequent rolling pass, the strip can be wound on a reel after several repeated passes through the rolling device, when the desired thickness of the rolled strip is reached. The strip-shaped material is arranged in the form of a coil or as a coil that has undergone a hot rolling process in a coil or flat sleeve, the strip-shaped material being received on a reel mandrel or reel head. The coil can be stretched on a reel head, which can be designed as an expansion head or a cone head, or the reel heads can be provided on both sides of the coil to accommodate the coil between them.

[0003] The reel head(s) are each arranged on a shaft, which is attached to the reel winding machine. This shaft is connected to an electric motor via a gearbox. A number of electric motors can be coupled to the gearbox to achieve different power increments. The shaft can be movably attached to the reel winding machine along its longitudinal axis so that the coil can be accommodated between the two reel heads. The electric motor, the gearbox, possibly a coupling and the frame on which these components are mounted thus form a reel. Such a reel is known, for example, from EP 2 896 465 B1.

[0004] In known reels, the material in strip form is wound up with a defined strip tension or tension created on the strip by the reel. This tension is set by the reel control device, in particular by control of the electric motor. For control purposes, the torque of the electric motor is calculated, from which the torque of the reel head or coil can then be determined. This torque can be determined, for example, from the input power of the electric motor and the current speed of the electric motor. However, since a gearbox, a coupling and possibly an intermediate shaft are interposed between the electric motor and the reel head, the torque reaching the reel head can be limited, for example due to the efficiency of the gearbox.

[0005] A drawback of known reels is that, due to their design, they require a relatively large installation space in the manufacturing facility. Moreover, each reel is always manufactured for a specific application and is therefore manufactured individually. Reel winding machines with electric motors, gearboxes, couplings and reel heads are always adjusted in such a way that increasing the power of the reel, for example by a more powerful electric motor, usually requires an increase in the drive train, and therefore, increasing the power of the reel by a more powerful electric motor is economically difficult to achieve. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide a reel and a method for pulling coils that allows for particularly cost-effective manufacture and operation. [Means for solving the problem]

[0007] This object is achieved by a reel having the features of claim 1, a modular system having the features of claim 13 and a method having the features of claim 14.

[0008] The reel according to the invention for winding or unwinding a strip-shaped material, in particular a metal strip, comprises a frame, at least one reel head on which a coil for winding the material is arranged, a drive having at least one electric motor, and a shaft connecting the electric motor and the reel head, the electric motor being formed with a stator and a rotor and arranged on the frame, the electric motor being a torque motor or a synchronous motor, the shaft connecting the rotor directly to the reel head, the rotor being mounted on the stator so as to be axially movable relative to the stator.

[0009] Since the electric motor is a torque motor or synchronous motor, it is possible to connect the reel head directly to the rotor via a shaft. Since the electric motor can generate a relatively large torque, it is not necessary to provide a gearbox interposed between the electric motor and the reel winder. Furthermore, the coupling, the necessary motor bearings and the reel winder itself can be omitted. Thus, the frame or the foundation required for the frame can be significantly reduced in size at the production site. In particular, the installation space of the reel and the size of the frame are determined only by the dimensions of the reel winder and the electric motor integrated in the reel head. Since a large part of the installation space and therefore the foundation that would otherwise be required can be saved, the reel can be manufactured in a particularly cost-effective manner and can be operated in an energy-efficient manner.

[0010] According to the invention, the rotor is mounted on the stator so that it is axially movable relative to the stator. This axial movability of the rotor relative to the stator can be realized by the rotor being axially movably mounted on the stator. Thus, the electric motor can be used like a reel winding machine known from the prior art. The coil can then be fixed particularly simply between two reel heads, i.e. the reel heads can be adapted to the length or position of the coil with respect to the longitudinal axis of the shaft.

[0011] Furthermore, the rotor is formed from a ring package, which is composed of several rings. In each ring, a magnet is arranged on the outer circumference of the respective ring or in an insert pocket directly below the outer circumference of the ring. The size of the magnet is limited to the dimensions of the respective ring, i.e. the magnet is not arranged on the ring so that it protrudes from the ring. The ring itself can be composed of a disk or a metal plate. The rings are connected to each other directly or indirectly. For example, the rings can be screwed to each other, i.e. detachably connected to each other. Furthermore, the rings can also be attached directly to the shaft or to the rotor carrier, which is arranged between the shaft and the inner diameter of the ring. The stator can surround the rotor, and the rotor can also in principle surround the stator. By using several rings to form the rotor, it is possible to make the electric motor modular in design. The number of rings can always be selected such that an electric motor is formed with the desired power without exchanging the stator. It is therefore possible to manufacture electric motors with different power levels using one stator. Thus, the production of individually designed reels can be standardized and thus particularly cost-effective.

[0012] The drive can be gearless, which makes the production of the reel even more cost-effective. In particular, in this case, no gear oil system is required. The efficiency of the reel can also be improved, since there are no friction losses due to the existing gearbox. Furthermore, the noise emission from the reel is also significantly reduced. Overall, the reel requires less maintenance, since it has fewer components.

[0013] The stator may be formed from a coil package having a plurality of coils and may surround a rotor, the rotor being formed from a ring package having a plurality of rings, each ring having a magnet on its outer periphery, the rings being connected to each other, and the length L of the ring package being 100 mm. R is the length of the coil package along the longitudinal axis of the shaft, L W The rotor travel range V is the difference in length V=L W -L R. The rotor can then be formed as an internal rotor. The stator can be formed by a stack of annular metal plates, on which the coils are integrally arranged. The annular metal plates can be surrounded by a frame to which the annular metal plates are fixed. Furthermore, the frame is formed with channels or pipes through which a cooling medium flows. If the length of the ring package is shorter than the length of the coil package, an increase in the power output of the electric motor can be easily achieved by adding rings to the ring package. The length of the coil package can always be the same for all electric motors used to form a reel, and the power output of the electric motor required individually for each reel can be adjusted by selecting the length of the ring package. It is advantageous to standardize the length of the stator or its coil package. If the length of the rotor package and the length of the coil package are substantially the same, no additional rings can be added to the electric motor. The possibility of an axial movement of the rotor is caused by the fact that the length of the coil package is longer than the length of the ring package. The range of movement resulting from the difference in length allows the rotor to move within this range of movement, without the result of such a movement changing the power output of the electric motor. This can be ensured in particular by ensuring that during operation the ring package is always covered by the coil package within its range of movement.

[0014] The drive may include at least one electric motor, each electric motor including a frame and a reel head, a coil disposed between the reel heads, and each coil package of the electric motor having a corresponding length L. WAs a result, the electric motors can be arranged on both sides of the coil. If the coil packages of the electric motors have corresponding lengths, the stators of the electric motors are designed substantially correspondingly. The electric motors can then be designed substantially identically or with different rotors. Since the coil packages do not have to be designed differently to form electric motors of different power, the electric motors can be manufactured and maintained more easily. Also, costs can be saved by mass-producing identical stators. Each of the electric motors can be arranged or mounted on a frame specially designed for this purpose, and the electric motors can also be arranged on a common frame. Then, the electric motors or the coils arranged between the reel heads can be moved on carriages guided on rails that cross the longitudinal axes of the two shafts of the electric motors, for example. A conveyor track thus formed for the carriages can be placed on a foundation specially formed for this purpose.

[0015] The power of the electric motors can be different or the same. The electric motors can be operated synchronously when winding the strip-shaped material. Furthermore, if a lower power is required, it is possible to operate only one of the two electric motors. If the electric motors are torque or synchronous motors, two or more power levels of each electric motor can be formed, since the input power of each electric motor can be electronically switched between two inverters, if required. Depending on the required overall reel power, the individual power of each of the electric motors can be designed accordingly and therefore can be the same or different.

[0016] Length L of each ring package of the electric motor RThe ring packages can be of different lengths. The length of the ring packages determines the amount of magnets around the circumference of each ring package and thus the power output of each electric motor. Electric motors with different power outputs can be easily formed based on the length of each ring package.

[0017] The rings can be different in width or the same. Since the ring package is formed from several rings, it is therefore possible to influence the length of the ring package. This can be done by using a certain number of rings to form the desired length and thus the power of the electric motor. The rings used can have corresponding widths or widths different from each other. If it is possible to select rings with different widths, it is possible to make the possible length of the ring package longer when forming the electric motor. If the ring package can be composed of several rings with two or three different widths, then a large number of possible variations in the length of the ring package arises.

[0018] The drive may comprise a tensioning device having an actuator, by which the rotor is axially movable relative to the stator. The actuator may be, for example, a hydraulically or pneumatically driven piston or linear motor. The actuator may be coupled to the shaft of an electric motor such that the movement of the actuator causes the shaft to move along the longitudinal axis. The rotor may then be moved relative to the stator by the actuator, and so the reel head may also be moved along the longitudinal axis. It is then possible to place the coil between the reel head, to pull the coil in the reel head, or to move the reel head into the coil, and / or to create a tension force between the reel head and the coil.

[0019] The rotor may be arranged on the shaft and may be attached to the housing of the stator by means of radial bearings and at least one axial bearing, with longitudinal guides being formed between the respective bearings and the housing on both sides of the rotor with respect to the longitudinal axis of the shaft. The bearings may preferably be plain and / or rolling bearings. The rolling bearings may for example be deep groove ball bearings, so that the bearings can absorb axial and radial forces. In this case, the radial and axial bearings may be formed by one bearing. The longitudinal guide may for example be formed by a sleeve which is movable in the direction of the longitudinal axis in a bushing. However, other types of longitudinal guides may also be used. The sleeve may be part of the housing of the stator, and the rotor is rotatably attached to the sleeve via radial or axial bearings. Preferably, the shaft may be attached to the housing on both sides of the rotor. It is thus possible that the rotor is rotatable relative to the stator and at the same time that the rotor is movable along the shaft and the longitudinal axis of the shaft. A longitudinal axis guide of this kind can be formed particularly simply, and the actuator can also be connected to the bushing. It can also be provided that the bushing is only axially movable in the sleeve. In principle, in addition to circular sleeves or bushings, any cross-sectional shape can be provided to form such a longitudinal axis guide.

[0020] The drive may comprise an additional actuator, by means of which the electric motor may be axially movable relative to the frame along the longitudinal axis of the shaft on an additional longitudinal guide formed in the frame. The additional actuator may be designed similarly to the actuator and may be arranged in the housing or frame of the stator. The additional actuator may then be coupled, for example, to a piston of the housing or frame, so that the movement of the piston causes a relative movement of the frame and the housing. An additional linear guide allowing a longitudinal movement of the electric motor may be formed between the housing and the frame. If the drive comprises several electric motors, each of these electric motors may be designed to be longitudinally movable in this way. In particular, the range of movement of the electric motors may be significantly expanded in this way, so that coils of different lengths may be accommodated on the reels.

[0021] The electric motor may be formed with a housing that may be mounted on a frame, with at least one force transducer of the detection device of the reel control device being arranged between the housing and the frame. This control device thus serves to control and adjust the reel, in particular the tension of the strip of the reel, which is formed by the tension of the strip in the strip wound by the reel into a coil. The electric motor generates a torque by means of a rotor, which is transmitted via the shaft to the reel head and thus to the coil. Depending on the amount of material contained in the coil, the diameter of the coil may vary greatly, so that the tension of the strip always depends on this diameter. The adjustment device of the control device may be designed in such a way that the relevant diameter is taken into account when adjusting the tension of the strip. Thus, in order to control the tension of the strip, the shaft torque may also be controlled by the control device. And this is usually performed by controlling the electric motor connected to the shaft. Since the electric motor is connected directly to the reel head via the shaft, without any gearbox, coupling or the like connected between the drive train, it is possible to measure the torque effectively acting on the reel head or the coils in the electric motor, and as a result of the direct power transmission it is conceivable that the torque can be measured very accurately. This direct force transmission makes it possible to measure the torque by means of a force transducer, which is fixed between the housing of the electric motor and the frame on which the electric motor is mounted. If the force transducer is fixed between the housing and the frame, the force to be measured is applied to the force transducer through the torque generated by the electric motor on the shaft, and a detection or control device can determine the torque of the shaft from the measured value. Only a direct connection between the electric motor and the reel head via the shaft makes this type of torque measurement possible, and thus makes it possible in particular to control the tension of the strip accurately.

[0022] The force transducer may be designed to detect compressive and / or tensile forces or torque. The force transducer may be a sensor, in particular a force sensor, a load cell or a load cell with which the force acting on the sensor can be measured. The force may be measured by a spring body, piezoelectrically, electromagnetically, electrodynamically or electroresistively. It may be intended that electroresistive sensors are not used, since they may be influenced by the magnetic field of the electric motor.

[0023] The force transducers may be spaced radially relative to the longitudinal axis of the shaft. From the radial spacing of the force transducers relative to the shaft, the torque may be easily calculated from the force measured using the force transducers.

[0024] The force transducer can be designed to detect compressive and / or tensile forces. Depending on the direction of rotation of the shaft relative to the direction of the tensile force of the strip, the force transducer can be exposed to a compressive or tensile force. It is particularly advantageous if the force transducer can be used to determine compressive and also tensile forces.

[0025] The housing can be fixed to the frame at a fixing point and the force transducer can be arranged at at least one fixing point. This fixing point can be formed, for example, by a screw connection between the housing and the frame. In principle, however, the fixing point can also be a support point of the housing on the frame.

[0026] It is particularly advantageous if force transducers are arranged at all fixed points, which makes it possible to detect all forces acting between the housing and the frame and thus to determine the torque of the shaft particularly accurately. However, this is not necessary in principle if the distribution of forces acting on the fixed points is known, since the torque can be determined using only one force transducer.

[0027] The force transducer can be arranged on the connection flanges of the housing and / or the frame. For example, the housing and the frame can form connection flanges with one another, which can abut on one another and be rigidly connectable to one another via a screw connection. The force transducer can then be arranged between these connection flanges. This can be sufficient for a preload of the screw connection to act on the force transducer. The detection device can be calibrated so that this preload is not taken into account or does not falsify the measurement result of the force transducer. Optionally, it is also possible to arrange the force transducer on the connection flanges so that it is not arranged between them, but spans the connection flanges. For this purpose, and the force transducer can be rigidly fixed to both connection flanges, so that the forces acting between the connection flanges are also transmitted to the force transducer.

[0028] The drive can have two reel heads, each of which is formed with a cone for receiving an expansion head or a coil. In principle, if the drive has only one electric motor, it can also be designed with one expansion head. The expansion head can be designed so that it can be inserted into an opening at one end of the coil. A part of the expansion head can then be fixed against the internal tension of the coil, so that the coil is firmly fixed in a press-fit manner and is located in the center of the expansion head. The actuation of this part can be performed hydraulically or by a drawbar. The cone can be designed to be supported at one end of the coil, so that the coil is fixed between two reel heads that can be moved relative to each other. In this case, the coil is also located in the center of the reel head.

[0029] The expansion head may have an expansion section device formed to radially pull the coil with the expansion section, and at least one hydraulic line is formed in the shaft or a drawbar for actuating the expansion section is arranged in the shaft. The shaft may therefore be designed as a hollow shaft or as a solid shaft. In principle, it is also possible to connect the hydraulic or mechanical actuation directly to the expansion head, i.e. to the expansion head itself, so that the shaft is not affected.

[0030] The modular system according to the invention for forming the reel according to the invention comprises a stator formed by a coil package having a plurality of coils, and a plurality of rings for forming a ring package of a rotor, each ring having a magnet on its outer circumference or in an insertion pocket just below its outer circumference, the rings being selected from a first set of rings having a first width and a second set of rings having a second width, which may be different from the first width. The modular system according to the invention can be used to form a rotor having a stator of various lengths L R This allows the formation of ring packages having a number of rings, so that electric motors having different outputs can be assembled from these ring packages or modular systems. Since different sets of rings are available for the selection of rings, a high degree of variability can be achieved while at the same time significantly reducing costs. Thus, the production of rotors and electric motors can be highly standardized and therefore particularly cost-effective.

[0031] In the method according to the invention for tensioning a coil for winding or unwinding a material in strip form, in particular a metal strip, by means of a reel, the rotor is moved axially in at least one electric motor of the drive of the reel relative to the stator of the electric motor, the electric motor being a torque motor or a synchronous motor, by a tensioning device of the drive such that the coil arranged between the reel heads is tensioned or released. For the advantageous effects of this method, reference is made to the description of the advantages of the reel according to the invention.

[0032] The axial movement can be used for strip center control and / or strip center alignment before or during the rolling operation. The strip center control is used to unwind the strip from a coil with non-straight edges and guide the strip centrally through the roll gap during rolling in order to wind the strip on a coil with straight edges. The strip center alignment is used to center the non-straight edged coil in the rolling line before rolling so that the wound strip is guided centrally through the roll gap. The position of the strip can be determined by sensors. Data from the sensors can be used for the control and thus for the axial movement.

[0033] The reel according to the invention is used for carrying out the method according to the invention. Further advantageous embodiments of the method are evident from the characterizing recitations of the dependent claims with reference to claim 1 of the device.

[0034] In the following, preferred embodiments of the reel are explained in more detail with reference to the drawings. [Brief description of the drawings]

[0035] [Figure 1] FIG. 1 shows a first embodiment of a reel in a longitudinal section. [Diagram 2] FIG. 2 shows a second embodiment of a reel in a longitudinal section. [Diagram 3] FIG. 3 shows a third embodiment of a reel in a longitudinal section. [Figure 4] FIG. 4 shows a fourth embodiment of a reel in a longitudinal section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] 1 shows a reel 10 for winding a material 11 in strip form or a metal strip into a coil 12. The reel 10 comprises two substantially similarly designed frames 13, two similarly designed reel heads 14 for arranging the coils 12, and a drive 15, which comprises two similarly designed electric motors 16 or torque motors. Each electric motor 16 is formed by a stator 17 and a rotor 18, the stator 17 surrounding the rotor 18, which is rotatably mounted within the stator 17. A rotor carrier 19 of the rotor 18 is non-rotatably arranged directly on a shaft 20 of the electric motor 16, which is directly connected to the reel head 14. Furthermore, the rotor 18 is formed from a ring package 21 consisting of a number of rings (not shown), each of which has a magnet at its outer periphery 22. The rings are detachably connected to each other. The stator 17 is formed by a coil package 23 having a number of coils (not shown), which are surrounded by a frame (not shown). Cooling channels 24 are formed in this frame, through which a cooling medium (not shown) flows, and serve to cool the coil package 23. Passive or surface cooling of the frame is also possible.

[0037] The electric motor 16 is further formed with a housing 25, which encloses the rotor 18 and the stator 17. The housing 25 is rigidly connected or screwed to the frame 13 at a fixing point 26. The frame 13 is rigidly connected to a foundation 28 at a fixing point 27. The housing 25 is further formed with a longitudinal guide 29, which allows the axial movement of the rotor 18 relative to the stator along the longitudinal axis 30 of the shaft 20. The longitudinal guide 29 is formed by sleeves 31 and 32 arranged on either side of the rotor 18 and bushings 33 and 34 surrounding the sleeves 31 and 32, respectively. The shaft 20 is mounted radially and axially in the sleeves 31 and 32 by means of a rolling bearing 35. The movement of the rotor 18 relative to the stator is possible within a movement range V, which is equal to the length L of the ring package 21.R and the length L of the coil package 23 W The possible movement is effected by an actuator 36, in this case formed by a hydraulic cylinder 37 and connected to the bushing 33 via a fastener 38. The possibility of moving the rotor 18 or the shaft 20 together with the reel heads 14 thus forms a tensioning device 39 which tensions the coil 12 between the reel heads 14.

[0038] In particular, the coil 12 driven directly by the electric motor 16 allows the number of rotating parts of the reel 10 to be significantly reduced, without the need for additional drive shafts, couplings, etc. In the event of a power outage or converter failure, the electric motor 16 can be braked by shorting the coil through a resistor, so no mechanical brake is required as a service brake for the reel. Furthermore, a stop brake is also not required, since a short circuit of the coil can be used to hold the rotor in its position when stopped. By reducing the number of parts and modules of the reel 10, maintenance costs can be significantly reduced.

[0039] Furthermore, it is possible to adjust or increase the power of the electric motor 16 by adding rings, even after the reel 10 is already in operation.

[0040] The drive device 15 comprises an additional actuator 40, which is arranged on the frame 13 and is formed by a hydraulic cylinder 41. The housing 25 is mounted on an additional longitudinal guide 42, which is formed on the frame 13 and is also axially movable in the longitudinal direction of the longitudinal axis by means of the additional actuator 40.

[0041] The reel heads 14 are each designed as an extension head 43, which has an extension part (not shown) that can be actuated via a hydraulic pipe (not shown) that can exert a clamping force on the inside 44 of the coil 12, so that the coil 12 is centrally located in the respective extension head 43 and fixed non-rotatably. The coil 12 with the material 11 can be transported to the reel 10 by a carriage 45, which can be moved on rails 46 laterally along the longitudinal axis 30.

[0042] Furthermore, a force transducer 47 is arranged on the housing 25 or on the fixed point 26 between the housing 25 and the frame 13. This force transducer 47 is a component of a control device (not shown), which serves to adjust the strip tension or the strip pulling force on the reel 10 or the power of the electric motor 16, and thus the torque. The control device comprises an adjustment device for adjusting the strip tension or the electric motor 16 and a detection device, which detection device comprises the force transducer 47. By arranging the force transducer 47 between the frame 13 and the housing 25, it is possible to determine the force acting between the frame 13 and the housing 25. Since the electric motors 16 are each directly connected to the coils 12 via the shaft 20 and the reel head 14, the torque of the respective electric motor 16 can be determined directly and thus particularly accurately via the force transducer 47 or the detection device, which allows an improved control of the strip tension.

[0043] 2 shows a reel 48 on which a frame 49 is formed without additional longitudinal guides, in contrast to the reel in FIG. 1. In this case, the tensioning device 39 is sufficient to tension the coil 50.

[0044] Figure 3 shows, in contrast to the reel in Figure 2, a reel 51 provided with a reel head 52 forming a cone 53 receiving a coil 54. This coil 54 is formed with an inner cone 56 at each end 55. In this way, the coil 54 can be received in the reel 48 in a press-fit manner, centrally located and non-rotatable, by fixing it between the reel heads 52.

[0045] Figure 4 shows a reel 57, which, in contrast to the reel in Figure 1, is provided with only the frame 13 and the electric motor 16. Instead of an additional electric motor, a counter bearing 58 is provided here. Attached to the shaft 20 of the electric motor 16 is a separating drum 59 which receives the coil 60 or a coil which has undergone a hot rolling process. In the case of a coil which has undergone a hot rolling process, the material 11 is placed directly on the separating drum 59 without the coil 60.

Claims

1. A reel (10, 48, 51, 57) for winding or unwinding a strip-shaped material (11), The reel is A frame (13, 49); at least one reel head (14, 52) on which a coil (12, 50, 54) for winding or unwinding material is disposed; a drive unit (15) having at least one electric motor (16); a shaft (20) connecting the electric motor and the reel head; The electric motor is formed with a stator (17) and a rotor (18) and is disposed on the frame; the electric motor is a torque motor or a synchronous motor; the shaft directly connects the rotor to the reel head; The rotor is provided on the stator so as to be movable in the axial direction relative to the stator. reel.

2. The stator (17) is formed of a coil package (23) having a plurality of coils and surrounds the rotor (18); The rotor is formed from a ring package (21) having a plurality of rings, Each ring has a magnet on its outer periphery (22); The rings are connected to each other; The length of the ring package (L Ｒ ) is the length (L) of the coil package along the longitudinal axis (30) of the shaft (20). Ｗ ) and The range of movement of the rotor (V) is the length (L Ｗ , L Ｒ 2. The reel of claim 1, wherein the difference corresponds to a difference of 1.

0.

3. The drive device (15) comprises a plurality of electric motors (16); Each of the electric motors includes a frame (13, 49) and a reel head (14, 52); a coil (12, 50, 54) disposed between the reel heads of each of the plurality of electric motors; The coil packages (23) of each of the electric motors have a corresponding length (L Ｗ 3. The reel of claim 2, further comprising:

4. 4. The reel according to claim 3, wherein the electric motors (16) have output magnitudes that are different from one another or equal to one another.

5. The length (L) of each of the ring packages (21) of the electric motor (16) Ｒ 5. The reel according to claim 4, wherein each of the first and second conductors is different from the other.

6. A reel according to any one of claims 2 to 5, characterized in that the widths of the plurality of rings are different from each other or the same as each other.

7. The drive device (15) comprises a tensioning device (39) having an actuator (36), A reel according to any one of claims 1 to 6, characterized in that the rotor (18) is axially movable relative to the stator (17) by the actuator.

8. The rotor (18) is disposed on the shaft (20) and is attached to a housing (25) of the stator (17) by means of radial bearings and at least one axial bearing; 8. A reel according to claim 7, characterized in that longitudinal guides (29) are formed on either side of the rotor about the longitudinal axis (30) of the shaft, between the respective bearings (35) and the housing.

9. The drive device (15) comprises an additional actuator (40), 9. A reel according to claim 7 or 8, characterized in that the electric motor (16) is movable axially relative to the frame (13, 49) along the longitudinal axis (30) of the shaft (20) by means of an additional actuator (40), in an additional longitudinal guide (42) formed in the frame.

10. The electric motor (16) is formed with a housing (25) attached to the frame (13, 49); A reel according to any one of claims 1 to 9, characterized in that at least one force transducer (47) of the detection device of the control device of the reel (10, 48, 51, 57) is arranged between the housing and the frame.

11. The drive unit (15) has two reel heads (14, 52), A reel according to any one of claims 1 to 10, characterised in that each reel head is formed with an enlarged head (43) or a cone (53) for receiving said coil (12, 50, 54).

12. The expansion head (43) has an expansion section device configured to radially tension the coil (12, 50) with an expansion section, 12. The reel according to claim 11, characterized in that at least one hydraulic line is formed in the shaft (20) or that a drawbar for actuating the expansion portion is arranged in the shaft (20).

13. A modular system for forming a reel (10, 48, 51, 57) according to any one of claims 1 to 12, comprising: a stator (17) formed by a coil package (23) having a plurality of coils; a plurality of rings for forming a ring package (21) of the rotor (18), each ring having a magnet on its outer periphery (22) or in an insertion pocket just below the outer periphery of the ring; the rings are selected from a first set of rings having a first width and a second set of rings having a second width different from the first width; Modular system.

14. 1. A method for pulling a coil (12, 50, 54, 60) on which a strip-shaped material (11) is wound or unwound by a reel (10, 48, 51, 57), comprising the steps of: a rotor (18) is moved axially relative to a stator (17) of the electric motor in at least one electric motor (16) of the drive (15) of the reel by a tensioning device (39) of the drive such that the coil arranged between the reel heads (14, 52) of the drive is tensioned or released, 4. The method according to claim 3, wherein the electric motor is a torque motor or a synchronous motor.

15. 15. The method according to claim 14, characterized in that the axial movement is used for strip centre control and / or strip centre alignment before or during a rolling operation.

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