EP2646883A1

EP2646883A1 - Concept for adjusting process parameters of a rolling process by means of a measured bearing slip

Info

Publication number: EP2646883A1
Application number: EP11790949.9A
Authority: EP
Inventors: Kurt Kemmer; Andreas Kern-Trautmann; Rupert Motschenbacher; Thomas Peuschel
Original assignee: SKF AB
Current assignee: SKF AB
Priority date: 2010-11-30
Filing date: 2011-11-29
Publication date: 2013-10-09
Also published as: DE102010062199B4; DE102010062199A1; CN103329053B; WO2012072603A1; CN103329053A

Abstract

The invention relates to a concept for regulating or controlling a plurality of process parameters (13-n) which determine an interaction of a plurality of rollers (11; 12) of a rolling mill (10) in a rolling process. A measured value (15) for a bearing slip of at least one rolling bearing (16) with which one of the rollers (11; 12) is supported is ascertained during the rolling process. At least one of the process parameters (13-n) is then adjusted on the basis of the measured bearing slip (15) such that the bearing slip of the roller (11; 12) lies in a predefined range containing a bearing slip target value during the rolling process.

Description

The present invention relates to a concept for controlling process parameters of a rolling process by means of a measured bearing slip.

Following various primary processes z. For example, sheets in different thicknesses and qualities can be produced by a variety of different rolling processes. The process of rolling can be considered as rotary pressure forming. It is possible to distinguish between hot and cold forming as well as longitudinal, transverse and inclined rolls. Most flat and profiled products are produced by longitudinal rolls in corresponding rolling mills. Under a rolling mill or a rolling mill is understood to mean a total of necessary for a rolling process mechanical assemblies, both for a forming and a rolling drive, as well as devices for introducing and exporting a rolling stock, which are engaged during a rolling process. Core elements of rolling mills are roller assemblies having a plurality of rotating, roller bearing rollers.

There are various roller arrangements, which can also be referred to as so-called rolling mills or rolling mills. There are, for example, horizontal and vertical scaffolding. In horizontal stands, several rotating rolls with horizontally oriented axes of rotation are vertically stacked in a stack, so that a rolling stock, such as an aluminum sheet, can be rolled horizontally from the superposed rotating rolls. For this purpose, it is processed by two work rolls, which can additionally be supported by support rolls in order to zen the rolling stock occurring partly high forces to compensate. For vertical stands, the axes of rotation of the rollers are aligned vertically.

The rolling is characterized by the power flows rolling drive, forming and neighboring aggregates, which are mainly coupled by the rolling stock with each other, so that one can speak of a power grid. In modern rolling mills, the rolling process in an information network is regulated by numerous, superimposed and linked process parameters or manipulated variables, such as rolling speed, rolling force, drive, strip thickness, strip tension, flatness, etc. The different modules are therefore both mechanically and electrically or electronically networked together, resulting in a complicated, heavily loaded, highly dynamic and sensitive overall mechatronic system.

It comes in such a rolling system repeatedly to rolling bearing damage by falling below necessary minimum loads in the application of backup roller bearings. This is due to the difficulty of predicting real load conditions and load cases in the application. As a result of frictional resistance caused by lubricant and bearing cage, a rotational speed of the rolling elements may decrease or even decrease to zero when the load on the bearing is very low. For certain rolls of a rolling mill, such as backup rolls, the bearing may get into such a zero load situation. Slipping of the rolling elements may result in a reduction in the thickness of the lubricating film or even failure of the entire lubricating film. Metal-to-metal contact may occur in the bearing, resulting in surface damage and possible damage to the bearing.

So far, rolling bearing loads are determined on the basis of theoretical load specifications by calculation models depending on bearing size and design. As a result, rolling process parameters are defined for rolling mills in order to always keep bearing loads above the respective minimum load. Due to different operating conditions, corresponding (multi-dimensional) application fields are prescribed in parameter maps which are provided with corresponding, sometimes high safety margins. These partly high security surcharges stand in the way of a tendency to ever higher productivity of rolling mills. It is therefore an object of the present invention to be able to operate rolling process parameters, such as rolling speed or rolling force, of rolling mills closer to their respective actual productivity limits, without, however, damaging rolling bearings of rotating rolls due to bearing slippage.

According to one aspect of the present invention, this object can be achieved by a control or regulation according to which a bearing slip of a rolling roller of the rolling mill measured during the rolling process is used as the controlled variable or variable to be controlled. A basic principle is therefore to measure a bearing slip of a roller bearing roller as a control variable or variable to be controlled (actual value) and depending on its deviation to a bearing slip setpoint by influencing (control) at least one process parameter manually or automatically (with an actuator) corrective intervene. By a possible feedback of the measured bearing slip, according to embodiments of the present invention, a closed control loop can also be created within the rolling process.

Exemplary embodiments provide a method for controlling a plurality of process parameters that determine an interaction of a plurality of rolls of a rolling mill in a rolling process. The method comprises measuring, during the rolling process, a bearing slip of at least one rolling bearing, with which one of the rolls is mounted, and adjusting at least one of the process parameters based on the measured value, so that the bearing slip of the roll during the rolling process in a predefined range a bearing slip setpoint is. Embodiments of the method can be executed manually or automatically.

According to a further aspect of the present invention, there is also provided a rolling mill with a plurality of rolls, the interaction of which in a rolling process is determined by a plurality of process parameters. The rolling mill comprises means for determining, during the rolling process, a bearing slip measurement for a rolling bearing supporting one of the rolls, and means for adjusting at least one of the process parameters based on the measured value so that the bearing slip of the roll during the rolling process Rolling process is in a predefined range to a bearing slip setpoint. As has already been described above, a rolling mill often also includes support rollers in addition to the actual work rolls in order to reduce a deflection of the work rolls in contact with the rolling stock. The device for determining the measured value of the bearing slip can be designed in accordance with exemplary embodiments in order to measure the bearing slip in at least one roller bearing with which one of the working and / or support rollers is mounted. For this purpose, it can, for example, measure a rotational speed of a rolling element in the rolling bearing and, based thereon, determine the measured value for the bearing slip. For speed determination, there are basically several alternative concepts, such as mechanical, optical, magnetic and / or electrical concepts. According to an exemplary embodiment, the means for determining the measured value may be designed to measure the bearing slip based on a magnetic field generated by a magnetized rolling element by means of an annular coil arranged approximately concentrically to a rotational axis of the rolling bearing. Additionally or alternatively, the measured value for the bearing slip can also be determined based on a slippage of a bearing cage of the rolling bearing. Accordingly, bearing slippage according to the present invention can be understood to include both rolling element slippage and bearing cage slippage. Also combinations of rolling element and Lagerkäfigschlupf can be subsumed under the term bearing slip here.

Preferably, the (predetermined) bearing slip setpoint is zero. That is, the means for adjusting may be configured to adjust at least one of the process parameters of the rolling process such that the bearing slip is substantially zero and thus a predefined minimum load of the roll is always reached or exceeded.

Furthermore, the device for setting the process parameters may preferably be designed to set at least one of the process parameters based on the bearing slip measured value such that an optimum, in the best case even maximum, productivity of the rolling process without bearing slip is achieved. This means that a rolling stock to be rolled, almost without bearing slippage, but at the same time can be produced particularly efficiently and by exploiting the highest possible performance of the rolling mill. The adjustable or controllable process parameters may be, for example, a rolling speed, a rolling temperature, a rolling force, or a roll spacing of the rolling mill. Of course, an adaptation of further rolling process parameters used in rolling mills is also possible and therefore encompassed by embodiments of the present invention.

Further advantageous developments and refinements of embodiments of the present invention are the subject of the dependent claims. If the measured bearing slip is thus outside of a tolerance range around the bearing slip setpoint, one or a plurality of the process parameters can be adjusted by manual or automatic regulation or control in accordance with the present invention, in order to return the measured bearing slip to its desired range (preferably, by Zero). Thus, with exemplary embodiments of the present invention, an optimized operating point can be set in a multi-dimensional parameter characteristic field of the rolling process.

Through a slip measurement on rolling elements and / or on a roller bearing cage, for example the back-up roller bearing, during operation, real rotational values can be detected with execution examples and danger areas of the slip can be detected. As a result, control processes or control can be intervened in the production process by adapting process parameters in order to prevent damage to the rolling bearing, reduce wear and increase the running time. By means of the present invention, damage in the case of use can be avoided by measuring real slip values. For this purpose, the measured values can be used to determine the characteristic value of a rolling mill control system, as a result of which not only marginal ranges of productivity can be safely approached without damaging roller bearings of the rolling mill.

Embodiments of the present invention will be explained below with reference to the accompanying figures. Show it: Fig. 1 is a schematic representation of a controlled rolling mill according to an embodiment of the present invention;

FIG. 2 shows a detailed illustration of a four-high rolling mill with two working and support rollers according to an exemplary embodiment of the present invention; FIG.

3 shows a depiction of a dependency of roll force F _w on a rolling speed n and other process parameters;

Fig. 4 is an enlarged view of a support roller of the roll stand of FIG. 2;

Fig. 5 is a still further enlarged view of the lower support roller according to FIGS. 2 and 3 with a device for determining a measured value for a bearing slip of the support roller, according to an exemplary embodiment of the present invention; and

6 is a schematic flow diagram of a method for controlling a rolling mill based on the bearing slip, according to an embodiment of the present invention.

Fig. 1 shows a schematic representation of a rolling mill 10 according to an embodiment of the present invention.

The rolling mill 10 has a plurality of supported rollers 11a, 11b and 12a, 12b, the interaction of which in a rolling process is typically determined by a plurality of rolling process parameters 13-1, 13-2, ..., 13 -N. Although in Fig. 1 the rollers are exemplarily arranged in a horizontal stand with two inner work rolls 1 la, b and two outer support rolls 12a, b, the present invention is equally applicable to other stands and arrangements such as e.g. Vertical scaffolding, applicable.

In addition to the rolls 11a, 11b and 12a, 12b, the rolling mill 10 comprises a device 14 for determining, during the rolling process, a measured value 15 for a bearing slip Sw of at least one rolling bearing 16b with which one of the rolls 12b is mounted. It is also means 18 for adjusting at least one of the process parameters 13-n (n = 1, 2, N) based on the measured value 15 so that the bearing slip Sw of the roller 12b lies in a predefined range around a specific bearing slip setpoint during the rolling process.

According to one exemplary embodiment, the device 14 for determining the measured value 15 is designed to measure or determine an actual rotational speed n _{w, g of} a rolling element of the roller bearing 16b and to determine the measured value 15 for the bearing slip Sw based thereon.

In order to determine the slip Sw of rolling elements in a (radial) roller bearing, in addition to the actual rotational speed n _{w, g of} the rolling elements, an actual rotational speed of an inner or outer ring of the rolling bearing should be known. If, for example, the rotational speed ni of the bearing inner ring corresponds to the rotational speed of a shaft or roller, a theoretical (slip-free) rotational speed n _{w of} the rolling elements can be determined according to the relationship n _w = -0.5 ni P / D _w (1-D _w / P cos a ) (1 - D _w / P cos a) (1). Here, ni is the rotational speed of the inner ring, D _{w is} the diameter of a rolling element, P is the pitch diameter and α is a contact angle of the rolling elements. For cylindrical rollers as rolling elements, for example, results in a contact angle of α

= 0 °.

The measured value 15 for the bearing slip Sw then results with the actually measured rotational speed n _{w, g of} the rolling elements

S _w = (1-n _w , _g / n _w ) 100%. (2)

In principle, any alternative concepts, such as, for example, mechanical, optical, magnetic and / or electrical concepts, or combinations thereof, can be used to determine the actual rolling body rotational speed n _{w, g} . In the following, however, the focus is placed on a concept for measuring the rolling-element rotational speed n _{w, g} by measuring and evaluating a magnetic field generated by at least one magnetized rolling element in the rolling bearing 16 b. A more detailed illustration of a possible roller arrangement is shown in FIG. Fig. 2 shows a rolling mill 20, which is formed by way of example only as a four-high rolling stand.

The four-high rolling stand 20 comprises a stack of rolls arranged vertically one above the other, wherein inside the stack there are two work rolls 11a, 11b and externally two support rolls 12a, 12b supporting the work rolls. The horizontal work rolls I Ia, I Ib exert a rolling or rolling force F _w on a rolling stock 21 to be passed between them. The roller force F _w results from laterally on the work rolls I Ia, I Ib on these exerted bending forces F, wherein the bending forces F may alternatively be directed up or down, as indicated by the corresponding arrows in Fig. 2. In order to reduce a deflection of the work rolls I Ia, Ib which are in contact with the rolling stock 21, they are supported by the support rolls 12a, 12b whose supports 16a, 16b have to receive support roll forces Fs _t . The bearings 16a, 16b of the two support rollers 12a, 12b comprise left and right two similar, juxtaposed radial roller bearings 22, which are prepared such that the rotational speeds of the therein rolling elements, such as cylindrical rollers, for determining the measured value 15 for the bearing slip Sw can be measured. This will be discussed in more detail below.

Although the predetermined bearing slip setpoint may generally be any value between 0% and 100%, a zero or 0% bearing slip setpoint is mostly of particular interest, as it can cause rolling bearing damage again and again in a rolling mill, for example, by falling below necessary Minimal loads and thus bearing slippage of roller bearings, in particular of backup roller bearings, come. This is illustrated in the operating point 31 shown in FIG. 3 in a characteristic diagram 30. The operating point 31 is located in a working area (shown in bright color) defined by various rolling process parameters, in which bearing slippage occurs.

3 shows an example of a rolling stock-dependent characteristic diagram. Shown is a dependence of the roller force F _w of a roller speed n at a predetermined support zenwalzkraft Fs _t and further dependent on various factors, such as an influence 33 of the bending force F. With certain settings of the rolling parameters results in an optimal work area or point 32. There is a difficulty in rolling processes, however, to predict real load conditions and load cases in different application or rolling scenarios and thus to hit the optimum operating point. Due to frictional resistances caused by lubricant and bearing cage, a rotational speed of the rolling elements in the bearings 22 may decrease or even decrease to zero if the load on the bearings 22 is too low, ie below a required minimum load. In some rolls, such as the back-up rolls 12a, b, a corresponding bearing 22 may get into such a zero-load situation, e.g. B. at high rolling speeds (speeds n) and low roll forces F _w (see Fig. 3). Sliding or rolling of the rolling elements in the bearing may reduce the thickness of the lubricating film, or even cause failure of the entire lubricating film, resulting in metal-to-metal contact, resulting in surface damage and possible bearing damage.

When the working point is adjusted by means of available rolling process parameters, it is therefore necessary to avoid bearing slippage of roller bearings, in particular of supporting roller bearings. Accordingly, in one embodiment, the adjustment means 14 is configured to set at least one of the process parameters 13-n (n = 1, 2, ..., N) based on the bearing slip measurement 15 such that a predefined minimum load of the ( Support roller 12b is always reached or (just so) is exceeded.

It is particularly advantageous with embodiments of the present invention to strive for a load limit range of the roller bearings rollers I Ia, B and 12a, b, in which it just does not come to a significant bearing slip. For example, the predetermined bearing slip setpoint could be between 0% and 5%. The means 18 for setting the process parameters can thus be designed in accordance with exemplary embodiments in order to set at least one of the process parameters 13-n (n = 1, 2,..., N) based on the bearing slip measured value 15, so that an optimum or even maximum productivity of the rolling process can be achieved substantially without bearing slip. This could be achieved, for example, with a constraint such that the individual process parameters 13-n (n = 1, 2, ..., N) are selected according to their maximum productivity, eg, as large or as small as possible. In the example of FIG. 3, the operating point 32 could thereby be displaced either vertically downwards in the direction of the slip area or horizontally to the right (in the direction of the slip area), for example by changing the bending force F and / or the rotational speed n.

The adjustable or controllable process parameters 13-n (n = 1, 2, N) may be, for example, already mentioned parameters such as the bending force F _b , support roll force Fs _t , rolling speed or speed n, rolling temperature, roll force or roll spacing the rollers I Ia, b and 12a, b of a rolling mill. Of course, an adaptation of other rolling process parameters used in rolling processes and influencing the bearing slip Sw is also possible and is therefore included in embodiments of the present invention.

Measuring the bearing slip and adjusting the at least one process parameter 13-n (n = 1,2, N), such. Example, one of the work rolls I Ia, b applied roll force F _w on a rolling stock 21 to be rolled, according to embodiments, once, for example, at the beginning of a rolling process, or periodically carried out within a rolling process. The bearing slip Sw of the bearings 22 is measured as a controlled variable or quantity to be controlled during the rolling process quasi as actual value and depending on its deviation from the predetermined bearing slip setpoint by means of the device 18 as an actuator by adjusting the process parameters 13-n (n = 1, 2, N) corrected automatically or manually. If the bearing slip measured value 15 corresponds to the predetermined bearing slip setpoint value, no further adjustment or adaptation of the rolling process parameters 13-n (n = 1, 2, N) has to be made. On the other hand, if it deviates from the bearing slip setpoint by more than a tolerance range, for example by more than 3%, a corresponding automatic or manual adjustment or readjustment of the rolling process parameters 13-n (n = 1, 2,. necessary.

The bearing slip measured value 15 can, according to some (automated) embodiments, be fed back as a control variable, similar to that shown in FIG. 1, whereby a closed bearing slip control loop for the rolling process can then be produced. In order to can in the rolling process in principle load-dependent and thus variable Lagerschlupf despite varying load situations of the working or support rollers I Ia, Ib, 12a, 12b automatically within certain limits constant (eg at about 0%) are kept. If, for example, one of the process parameters 13-n (n = 1, 2, ..., N) and thus also the bearing slip is changed, another of the process parameters 13-m (mn; m = 1, 2,. .., N) are automatically readjusted in order to obtain the specified bearing slip setpoint again. Likewise, the setting of the process parameters 13-n (n = 1, 2,..., N) can be adapted to different rolled products 21 by the present invention. Thus, for example, sheet metal can be rolled from the same rolling mill in a first rolling process and steel in a second rolling process, with the respective process parameters 13-n (n = 1, 2, Productivity limits can be introduced.

As already mentioned, fundamentally different concepts can be used to determine the actual rolling body speed n _{w, g} . In the following, however, a concept for measuring the rolling-element rotational speed by measuring and evaluating a magnetic field generated by a rolling element provided with a magnetization will be described in more detail. The Fign. 4 and 5 show enlarged views of the support roller bearing 16a shown in FIG. 2 with a measuring device for the rolling element and bearing ring speeds.

As is apparent from Fig. 4, the support roller bearing 16a comprises two adjacent, similar radial roller bearings 22 in order to achieve the most symmetrical load. Each of the radial roller bearing 22 comprises a bearing inner ring 41 and a bearing outer ring 42. The inner ring 41 of the radial roller bearing 22 is clamped onto a shaft of the roller 12a and braced with this with a retaining ring 43 which is screwed to the shaft. Between bearing inner and outer bearing ring 42 cylindrical rollers 44 are each arranged in two rows as rolling elements. In intermediate spaces between the rolling elements 43 by means of a lubricant supply 45 lubricant, such as oil, are placed in the bearings 22. On a front side of the bearing assembly, a bearing housing cover 46 is fastened by means of different fastening screws 47. In the bearing housing cover 46, a sensor 48 is also provided to measure a Lagerkäfigschlupf. As it is 5, a magnetic coil 50 and a cable feedthrough 51 assigned thereto are provided in order to be able to measure a rotational speed n _{& w} and thus also a slip of the rolling bodies 44. The magnet coil 50 is fastened to the housing cover 46 with a fastening screw 52.

The speed _{w of} the rolling elements 44 and a bearing cage 53 need only be measured in the axially outer radial rolling bearing 22. For this purpose, the axially outer radial roller bearing 22 is specially prepared for the measurement, as can be seen in particular from FIG.

The measuring device shown in FIG. 5 in particular allows the measurement of a slip Sw of a rolling element 44. For this purpose, at least one rolling element 44 of the radial roller bearing 22 is magnetized such that its magnetization direction is perpendicular to the axis of rotation of the rolling element 44.

Laterally next to the radial rolling bearing 22 to be measured, the annular measuring coil 50 is arranged, the radius of which corresponds approximately to a roller pitch circle radius. The magnetized rolling element 44 generates an oscillating magnetic flux during a rolling movement through an area enclosed by the measuring coil 50. The surface of the coil 50 is circular and concentric with the axis of rotation of the radial roller bearing 22. The measuring coil 50 is connected via the cable feedthrough 51 in connection with the device 14 schematically shown in FIG. 1 for determining the bearing slip measured value 15, which induced in the measuring coil 50 and by the measurement voltage generated by the oscillating magnetic field generated by the rolling body 44 receives and evaluates to determine the measured value 15 for the bearing slip Sw. The measuring coil 50 therefore forms a magnetic field sensor for the device 14 for determining the bearing slip measured value.

The magnetic field generated by the magnetized rolling element 44 is transmitted via the inner ring 41 to the roller shaft and the clamping ring 43, through the narrow gap on the fastening ring and thus through the measuring coil 50 via a housing of the measuring device on the outer ring 42 of the radial roller bearing 22nd transmitted, so that so closed magnetic field lines and the measuring coil 50 go through. The bearing cage 53 may be formed, for example, brass and two parts. The bearing cage 53 may comprise, according to embodiments, a bore (not shown) into which a pin may be inserted serving as a positioning means. The inductive proximity sensor 48 of the measuring device can then generate a current pulse each time the positioning means is guided past the proximity sensor 48 after a rotation. As a result, a rotational movement of the bearing cage 53 can be determined independently of the rotational speed of the rolling elements 44 and independently of the rotational speed of the bearing inner ring 41. Since the position of the magnetized rolling element 44 is uniquely determined by the rotational position of the bearing cage 53, the position of the rolling element 43 on the inner and / or the outer raceway can be calculated therefrom by means of the device 14. The device 14 for determining the measured value 15 can thus be designed to additionally or alternatively measure the bearing slip Sw based on a slippage of a bearing cage 53 of the roller bearing 22. Having previously explained various embodiments of the present invention in detail, a method 60 according to the invention for controlling a plurality of process parameters 13-n (n = 1, 2,..., N), which interacts, will be described below with reference to FIG determine a plurality of rolls of a rolling mill in a rolling process can be explained. Such a method can be carried out automatically, for example by means of an inventive rolling mill with the described measuring and control devices, or manually.

For this purpose, the method comprises a first step 62 in which, during a rolling process, the bearing slip Sw of at least one rolling bearing 22, with which one of the rolls of the rolling mill is mounted, is measured. A possible measurement concept by means of an evaluation of rotating magnetic fields was explained in detail above.

In a further step 64, at least one of the process parameters 13-n (n = 1, 2, N) is set based on the measured bearing slip 15, so that the bearing slip Sw of the roller during the rolling process in a predefined area around the bearing slip setpoint (FIG. preferably zero). In particular, at the same time maximum productivity of the rolling process is desirable. It has already been described above that the setting can be made both automatically, for example in the form of a control loop, as well as manually, which is why this should not be repeated here. A functional description of the bearing slip Sw is complicated and depends inter alia on various rolling process parameters 13-n (n = 1, 2, N), such as a material to be rolled, a take-off or rolling speed (directly affects the rolling speed n), the bending forces F and the column rolling forces Fs _t . By measuring the bearing slip Sw, according to exemplary embodiments, for example, influence can be exerted on the take-off or rolling speed, the bending forces F _b and / or the column rolling forces Fs _t in order to avoid bearing damage. The bearing slip measured values 15 can be determined depending on the material and the manipulated variables can either be controlled manually or automatically fed into the control in order to generate control.

LIST OF REFERENCE NUMBERS

10 rolling mill

11 stripper

12 support roller

13 process parameters

14 Device for determining a measured value for a bearing slip

15 measured value for bearing slip

16 back-up roller bearings

18 Device for setting at least one process parameter

20 rolling stand

21 rolling stock

22 Radial rolling bearings

30 map

31 operating point with bearing slip

32 operating point without bearing slip

33 influences on operating point

41 bearing inner ring

42 bearing outer ring

43 clamping ring

44 rolling elements

45 Lubricant supply

46 housing cover

47 housing screw

48 Bearing cage slip proximity sensor

50 measuring coil for rolling element slip

51 cable entry

52 retaining screw

53 bearing cage

Claims

P atentansprü concept for adjusting process parameters of a rolling process by means of a measured bearing slip

A rolling mill (10) having a plurality of rollers (11; 12) whose interaction in a rolling process is determined by a plurality of process parameters (13-n), comprising: means (14) for determining during the Rolling process, a measured value (15) for a bearing slip of a rolling bearing (16; 22) with which one of the rollers is mounted; and means (18) for adjusting at least one of the process parameters (13-n) based on the measurement (15) so that the bearing slip of the roll (11; 12) during the rolling process is within a predefined range around a bearing slip setpoint.

2. The rolling mill of claim 1, wherein the bearing slip setpoint is zero, and wherein the means (18) for adjusting is configured to set the at least one process parameter (13-n) based on the measurement (15) such that a predefined minimum load the roller (1 1, 12) is always reached or exceeded.

3. The rolling mill of claim 1, wherein the adjusting device is configured to set the at least one process parameter based on the measured value such that a maximum productivity of the rolling process is essentially zero Stock slip is achieved.

4. The rolling mill according to one of the preceding claims, wherein the rolling mill has work rolls (11) and these supporting support rolls (12), and wherein the means (14) for determining the measured value (15) is designed to prevent bearing slippage in a rolling bearing ( 22) with which one of the support rollers (12) is mounted.

5. The rolling mill according to one of the preceding claims, wherein the means (14) for determining the measured value (15) is adapted to measure a rotational speed ( _w ) of a rolling body (43) and based thereon the measured value (15) for the bearing slip to investigate.

6. The rolling mill according to one of the preceding claims, wherein the means (14) for determining the measured value (15) is adapted to the bearing slip based on a magnetic field generated by a magnetized rolling elements (43) by means of a in about concentric with the axis of rotation of the bearing (22) arranged ring coil (48) to measure.

The rolling mill of any one of the preceding claims, wherein the means (14) for determining the measurement (15) is arranged to measure bearing slippage based on slippage of a bearing cage (53) of the rolling bearing.

8. The rolling mill according to claim 7, wherein in the bearing cage (53) a positioning means is provided, whose position for measuring the position and / or rotational speed of the cage is measured.

The rolling mill of any one of the preceding claims, wherein the at least one process parameter (13-n) is a rolling speed, a rolling temperature, a roll force, or a roll spacing.

10. A method (60) for controlling a plurality of process parameters (13-n) that determine a cooperation of a plurality of rolls (11; 12) of a rolling mill (10; 20) in a rolling process, comprising the steps of:

Measuring (62), during the rolling process, a bearing slip of at least one roller bearing (16; 22), with which one of the rollers (11; 12) is mounted; and Adjusting (64) at least one of the process parameters (13-n) based on the measured bearing slip (15) so that the bearing slip of the roller (11; 12) is within a predefined range around a bearing slip setpoint during the rolling process.