DE102015009833B3 - "Bearing for a roll neck of a roll or for a roll shaft of a roll stand and roll stand" - Google Patents

Abstract

Bearing for a roll neck of a roll of a roll stand or for a roll shaft or for the roll neck or the roll shaft supporting eccentric bush, characterized by a base body (2) and at least one in the base body (2) for contact with the roll neck or the roll shaft or the Exzenterbuchse (1) arranged piezoelectric element (3, 10, 11).

Description

The invention relates to a bearing for a roll neck of a roll or for a roll shaft of a roll stand or for a roll neck or the roll shaft supporting eccentric bushing. Likewise, the invention relates to a rolling stand with such a bearing. The invention further relates to a method for radially adjusting the roll of such a roll stand.

From the German Offenlegungsschrift 22 59 143 it is in a possible field of application of the invention, namely the rolling stands for rolling rod or tubular Well known, at least one of the described there to form a caliber star-shaped around the Walzgutlängsachse arranged three rollers, the two end-side roll neck or the roll shaft in each case rotatably support an eccentric bushing. Such eccentric bushes have an inner, circular recess in which the radial bearing, preferably a radial roller bearing, the roll neck or the roller shaft is located, and a circular outer periphery, on which the bearing of the eccentric bush is provided in the housing of the rolling stand. The eccentricity of the eccentric bush results from the fact that the inner circle formed by the inwardly facing surface of the eccentric bushing and the circle formed by the outwardly facing outer surface of the bushing are not made coaxial. Like in the German Offenlegungsschrift 22 59 143 is explained in more detail, such constructions can be used for hiring the rolls of such a rolling stand, so for example for delivery to the rolling stock.

The German Offenlegungsschrift 22 59 143 further describes Anstellmechanismen for the movement of the eccentric bushing in a desired rotational position relative to the housing. About a arranged on a rotatable adjusting spindle Anstellzapfen is a rotational movement of a Anstellwelle with a collar via a transmission lever which is pivotally connected to both the adjusting ring and the eccentric bush, transmitted to the eccentric bushing. Alternatively, a fixedly mounted in the axial direction threaded spindle is provided, on which a threaded bush moves in the axial direction. About a hinge, the threaded bushing is connected to a collar, which in turn encloses a bush-like approach of the eccentric bushing and is rotatably connected by a feather key with this. These adjusting mechanisms make it possible to rotate the eccentric bushing with respect to the housing in which it is mounted. Fixing the threaded spindle prevents the threaded spindle from rotating, so that the eccentric bushing is held in the set, desired position via this fixing.

From the German Offenlegungsschrift 22 59 143 Thus, it is generally known that it is advantageous if a roll stand offers the possibility of roll adjustment. This means that the rolls can be delivered radially to the rolling stock in order to change the finished diameter of the rolling targeted, or compensate for influences by heat shrinkage of the rolling stock or wear of the rollers.

In the German Offenlegungsschrift 22 59 143 It is envisaged that the eccentric bushing has a slide bearing in the housing, that is, the outer surface of the eccentric sleeve slides on a surface of the housing when adjusting the eccentric bushing. This entails that the employment is only possible if no rolling stock is currently in the framework. Otherwise, the eccentric bushing is under the influence of the rolling force, so that increased, tangentially acting adhesive or sliding friction forces occur between the scaffold housing and the eccentric sleeve.

Out DD 272 686 A1 a method for moving a component on the sliding guides of a subset of machine tools is known. There, a method for moving a component on the sliding guides of a pedestal, in particular on machine tools, described, wherein the moving member has a longitudinal guide with a guide surface and is placed on the mating surface of the sliding guide by the action of a feed force from the rest state in a moving state , Wherein the longitudinal guide and / or the sliding guide before the action of the feed force relative to the moving component and the subset by the action of pulses by small distances is moved back and forth. To generate the pulse oscillation, electromagnetic oscillating armatures, piezoelectric encoders, mechanical oscillators or fluid-driven oscillators are proposed.

Out DE 10 2006 021 010 B4 a joint and / or bearing assembly with a joint or bearing body is known, which is movable relative to a receiving joint shell, wherein the joint and / or bearing assembly associated with at least one actuator for recording an alternating application of force between the joint or bearing body on the one hand and joint shell on the other wherein the actuator introduces a periodic clocked movement in the joint, so that at least the joint or bearing body or the joint shell are alternately set in motion about the central axis.

Out US 3,620,061 A it is known, within a bore of a roll, a plurality of radially poled ceramic rings made of zinc-citrate Titanium ceramic are to be arranged and to use them as radially polarized piezoelectric rings.

Against this background, the invention has the object to provide a bearing for a roll neck of a roll stand or a roll shaft or a roll neck or roll shaft supporting eccentric bushing, which allows a hiring of the roller even during rolling. A further object of the present invention is to provide a rolling stand and a method for setting the roll of a roll stand, which allow a simpler setting of the roll of the roll stand.

This object is achieved by the subject matters of the independent claims. Advantageous embodiments are given in the subclaims and the description below.

The invention is based on the basic idea of carrying out the bearing for the roll neck of a roll stand or a roll shaft or an eccentric bushing with a base body in which at least one piezoelectric element is arranged for contact with the roll neck or the roll shaft or the eccentric bushing. To simplify the following description of the invention, this will be described with reference to the embodiment of an eccentric bushing. However, the following statements apply equally to the direct storage of a roll neck or a roll shaft.

The use of a piezoelectric element in a bearing for the eccentric bushing of a roll stand offers advantages in various aspects. On the one hand, the piezoelectric element of the bearing can be excited in an oscillating manner. Under an oscillating excitation, the rapid sequence of a first excitation of the piezoelectric element, in which the surface of the piezoelectric element facing the roll neck moves away from the base towards the eccentric bushing, is understood to be a second excitation in which this surface is relatively moved to its final position at the first excitation away from the eccentric bushing. The excitation is preferably very high frequency. Then the eccentric bushing can not follow the movement of the surface of the piezoelectric elements due to their own inertia of the movement, which in turn causes the contact between the eccentric bush on the one hand and the surface of the piezoelectric elements on the other hand is canceled during a certain time portion of each excitation cycle.

Further, it is also possible to provide on one and the same eccentric bushing two or more groups of such oscillating excited piezoelectric elements, wherein the excitation in push-pull (two groups) or with a temporal offset of T / n (where T is the period of oscillation and n the number of separately excited groups of piezo elements is). This ensures that there is always a contact between the surface of the piezoelectric elements and the surface of the eccentric bushing, whereby the normal force resulting from the rolling force between the eccentric bushing on the one hand and the bearing unit equipped with piezoelectric elements on the other hand is transmitted optimally and without a time interruption.

In a preferred embodiment, during a rotational movement (setting movement) of the eccentric bushing, those piezo elements which are currently in contact with the surface of the eccentric bushing, determined by the phase of the oscillatory movement, follow the relative movement of the surface of the eccentric bushing laterally (ie tangentially to the surface) Scope of the eccentric bush) deflected and thereby elastically deformed. As soon as these elements then move away from the surface of the eccentric bushing due to their oscillating excitation and lose contact with it, this lateral deflection force is eliminated and the elements return to their non-laterally deflected position. In the next phase of their oscillating excitation, these piezoelectric elements then get back in contact with the eccentric bushing, whereby the piezoelectric elements of the second, time-delayed controlled group are then relieved and in turn return to their non-laterally deflected position, etc.

Such an oscillating excitation of a piezoelectric element leads de facto to the fact that the friction between the mutually facing surfaces of the eccentric bush and the body is significantly reduced. As a result, a relative movement between the eccentric bushing and the bearing can take place with an extremely reduced expenditure of force, which makes the employment of the rollers much easier. In addition or as an alternative, piezoelectric elements on the eccentric bush of a roll stand can also be used as actuators for the setting itself. According to a preferred embodiment described below, the piezoelectric elements are driven as a stepping drive. Thus, the piezoelectric elements themselves can be used to produce a relative movement between an eccentric bushing and the main body of the bearing. As a result, an adjustment of the roll can be carried out in the rolling stand. These two advantages can be combined. Thus, various groups of piezoelectric elements can be provided. Some may be used to reduce friction, while others are used as a stepper drive.

In this embodiment of the rolling mill according to the invention, the eccentric bushing is not as in DE 2 259 143 A or DE 10 2006 009 173 A1 via an intermediate needle bearing, but at least partially by means of provided with piezoelectric bodies, which may for example take the form of half-shells, stored in the housing. The piezo elements are particularly preferably arranged radially to the roller axis.

If the Anstellwirkung to take place, the piezo elements are excited with a high-frequency alternating voltage, for example 40 kHz. As a result, the static friction can be almost completely eliminated, which in turn allows easy rotation of the eccentric sleeve even under rolling force.

The bearing according to the invention is suitable for supporting a roll neck of a roll or the roll shaft of a roll stand or for supporting an eccentric bush supporting the roll neck or the roll shaft. Usually, a bearing for a roll neck is understood to mean an element which completely surrounds the roll neck or the eccentric bush once in the circumferential direction. A particularly preferred embodiment of the bearing according to the invention therefore provides that the bearing is designed to completely enclose a roll neck of a roll or a roll shaft of a roll stand or an eccentric bushing in the circumferential direction. This can be achieved, for example, in that the base body of the bearing has a circular recess into which the roll neck or the roll shaft can be inserted or into which the eccentric bushing can be inserted. In such an embodiment, however, it is not necessary that are arranged on the entire circumference of the circular recess facing surface of the base body piezoelectric elements for contact with the roll neck or the roller shaft or the eccentric bushing.

However, it has been found that the friction forces to be overcome for a simple setting of the rollers, depending on the type of employment occur only in certain areas of the circumference of the eccentric bushing. In the case of a radial setting of a roll in a roll stand, in which the roll must be moved perpendicular to the roll axis, the frictional forces to be overcome usually occur only on the side of the eccentric bush facing away from the rolling stock. The rolling rolled between the rolls of the rolling stand exerts a force on the rolls, which points away from the rolling stock. In the same way, each roller exerts a force on the bearing supporting it (or the eccentric bush on the bearing supporting it), which also points away from the rolling stock. It is primarily this normal force that produces tangentially acting frictional forces between the eccentric bushing and the bearing that would have to be overcome when starting up under load. Due to the direction of the normal force, these frictional forces essentially occur on the side of the eccentric bush facing away from the rolling stock. The advantages according to the invention can therefore already be achieved if the bearing for the eccentric bush with its base body and the piezoelectric elements arranged therein extends only over the region in which the essential frictional forces between the eccentric bush and the bearing occur during operation. In order to achieve the advantages according to the invention, the bearing thus does not have to completely enclose the eccentric bushing in the circumferential direction. In a preferred embodiment, the surface of the bearing facing the roll neck or the roll shaft or the eccentric bushing extends only over the surface of a sheet. The remaining part, which is necessary to completely enclose the roll neck or the roller shaft or the eccentric bushing in the circumferential direction, can be formed by a bearing, in whose base no piezoelectric elements are embedded.

The invention may offer the advantage that the piezoelectric elements only in the region of the load zone between eccentric sleeve and scaffold, d. H. So on the side facing away from the rolling stock of the roll shaft, must be arranged, but not on the rolling stock facing side of the eccentric bushing. On the rolling stock facing side of the eccentric bush, the space is regularly limited. Particularly in the case of the particularly preferred designs with three or four shafts, the installation space on the side facing the rolling stock is very limited by the adjacent other roll shafts.

In a particularly preferred embodiment of the invention, the bearing has a plurality of piezoelectric elements arranged in the base body for contact with the roll neck or the eccentric bushing.

It has been shown that when using a plurality of piezoelectric elements, the effects of the invention, in particular preferably the reduction of friction between the mutually facing surfaces of the main body of the bearing and the roll neck or eccentric bushing can be achieved.

In a preferred embodiment, the piezoelectric elements are divided into two or more groups and controlled such that the groups are driven at the same frequency, but with a time offset. In the case of two groups of Piezo elements means that the first group is in push-pull to the second group. This can create the effect of swimming between the roll neck and the bearing. "Push-pull" here means that the piezoelectric elements of the one group in the respective time unit in a first direction (for example in the Ausdehnrichtung) are driven, while the piezoelectric elements of the second group in the same time unit in the opposite direction (here, for example, in the contraction direction) are controlled.

In a particularly preferred embodiment, adjacent piezoelectric elements belong to different groups. A first piezoelectric element thus belongs to the first group, the piezoelectric element adjacent to it belongs to the second group, the piezoelectric element, which in turn is adjacent to the first group, etc. It has been found that in this arrangement, in particular, a swimming between whose facing surfaces of the main body of the bearing and the roll neck or eccentric bushing can be achieved particularly well.

In a preferred embodiment, a piezoelectric element is used which has a working stroke of a few hundredths of a mm.

In a particularly preferred embodiment, piezoelectric elements are provided, which are controlled as a stepping drive. The possibility of constructing a step drive with a piezoelectric element is, for example, in EP 0 552 346 A1 . DE 41 32 775 A1 . EP 0 613 586 A1 . EP 1 116 283 A1 . EP 1 086 499 A1 . DE 101 27 444 A1 . DE 101 13 744 A1 . EP 1 384 308 A2 . EP 1 705 492 A1 . EP 2 013 965 A1 . EP 2 356 705 A2 . EP 2 711 509 A2 . EP 2 749 442 A2 described.

The stepping drive offers the possibility of rotational adjustment by individually arranged in the frame, acting directly on the respective eccentric bushing actuators. This makes it possible, both the one and the same roller shaft between the eccentric bushes required in the prior art mechanical synchronization, such as by the bracket 10 in the 3 of the DE 2 259 143 , as well as the bevel gears provided for synchronization between the eccentric sleeves (see bevel gear tooth ring 11 in FIG DE 2 259 143 A ) to avoid. This may allow the eccentric sleeve to be pivoted about the maximum possible pivoting angle of approximately 180 °. Compared to the prior art can thereby considerably increase, in some cases even twice, without increasing the eccentricity and thus without limiting the roll width or space of the radial bearing of the Anstellbereich the framework.

The rotationally acting actuators may be electromechanical, hydraulic or in particular also piezoelectric actuators.

The use of a walking drive basically offers further adjustment options. For example, it is conceivable to provide two opposing groups of piezoelectric elements, wherein the piezoelectric elements of each group each extend along a line. Between the piezoelectric elements of the first group and the piezoelectric elements of the second group, a wedge is arranged. The two groups of piezoelectric elements can now be controlled in such a way that the piezoelectric elements travel along the surface of the wedge. In accordance with the increasing thickness of the wedge, the distance between the two groups of piezoelectric elements is increased. This increase in the distance between the two groups of piezoelectric elements can be used, for example, to change the position of the bearing bush in the framework housing, whereby the distance of the roll axis from the rolling axis is changed ("roll adjustment"). It is also conceivable that a stepping drive made of piezoelectric elements is used to rotate a spindle, with which an adjustment of the rollers is carried out in the rolling stand.

The electronics used to drive the actuators can be arranged in a compact, easily replaceable unit within the rolling stand. The signals required for employment can be transmitted wirelessly to the actuators in the rolling stand by the central electronics located outside the rolling stand. The energy required for the adjustment is advantageously also transferred to the scaffolding without direct contact. Here is an inductive energy transfer from the billet to the respective rolling mill conceivable. And likewise, a high-performance battery arranged in the roll stand is conceivable. Finally, "energy harvesting" in the framework is also conceivable in that, for example, electric energy is branched off from the shaft rotation by induction from a shaft arranged on a roller shaft and temporarily stored in a high-performance battery.

Finally, the invention with the possibility of mechanically independently acting adjusting the eccentric bushes also offers the possibility that - in a small scale - by selectively non-synchronous employment of the individual roller shafts (in the roller workshop, before the axial adjustment of the rollers is made), the caliber center can be moved relative to the outer contour of the frame. This could be compensated, for example, wear of regularly provided with such rolling stands slide strips.

The rolling mill according to the invention has at least one roller with at least one roll neck or a roll shaft or an eccentric bush, which is mounted in a bearing according to the invention. In a preferred embodiment, the bearing is arranged relative to the roll neck or to the roll shaft or to the eccentric bush in such a manner in the roll stand, that it serves as a radial bearing. However, it is also conceivable that the bearing according to the invention is arranged relative to the roll neck of the roll or to the roll shaft or to the eccentric bush in the roll stand such that it serves as a thrust bearing.

In an alternative embodiment of the roll stand according to the invention, this has at least one roll with two roll necks, which are each rotatably mounted in an eccentric bush, or at least one roll shaft, which is mounted on either side of the roller in a respective eccentric bush, each eccentric rotatable about a bearing according to the invention is mounted in the housing of the roll stand. In this case, the execution of the roll stand or the eccentric bushing can be designed as in DE 10 2006 009 173 A1 or DE 2 259 143 A described, with the difference that the needle bearing is at least partially replaced by a bearing according to the invention.

In a preferred embodiment, the bearing is designed as a slot which can be inserted into a receptacle of the housing of the rolling stand and which can be fixed in the receptacle for receiving and transmitting forces to the housing. This offers the advantage that the piezoelectric elements can be easily serviced or replaced.

The method according to the invention for radially setting up a rolling stand according to the invention provides that the piezoelectric elements of the bearing are oscillated, so that the friction between the eccentric bush and the roll neck is reduced and the roll is radially adjusted by rotation of the eccentric bushing.

The invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment. It shows:

1 an outline sketch of the elements used for the bearing according to the invention in a plan view along the axis of the roller shaft;

2 a sketch of a first operating state of a piezoelectric element of the bearing according to the invention in a plan view;

3 a sketch of a second operating state of a piezoelectric element of the bearing according to the invention in a plan view;

4 a sketch of an embodiment of the bearing according to the invention with two groups of piezoelectric elements in a plan view;

5 a sketch of a portion of the rolling mill according to the invention, in which a bearing according to the invention is provided, which is formed in the housing of the roll stand inserted in a plan view and

6 one to the view 5 Comparable view of another embodiment, in which a stepping drive is additionally provided for generating a setting movement in the form of two further, mutually opposite slots, in a plan view along the axis of the roll neck.

In 1 is an eccentric bush shown in detail only with respect to its outer periphery 1 shown. The eccentric bush 1 is intended to support a roll neck not shown in detail or a non-illustrated roller shaft of a roll of a roll stand. This can be done after the in DE 2 259 143 done in more detail.

In 1 is also a basic body 2 a warehouse according to the invention shown. This basic body 2 is in the in 1 illustrated embodiment is annular and surrounds the eccentric bushing 1 , The main body 2 in turn is held in a scaffold housing not shown in detail of a roll stand.

This in 1 illustrated bearing according to the invention has a plurality of in the body 2 for contact with the eccentric bush 1 arranged piezoelectric elements 3 on. These extend radially to the main body 2 in the direction of the eccentric bush 1 out. The respective piezoelectric element 3 can be controlled so that its for contact with the eccentric bushing 1 provided surface in the radial direction at a first control of the surface of the eccentric bushing 1 on and on another control on the surface of the eccentric bushing 1 to be moved.

To illustrate the overall structure within a rolling stand according to the invention is in the 1 a part of a roller 4 shown, the (not shown) roll pin in the eccentric bushing 1 is supported. Further, a rolling stock 5 represented in the form of a pipe or rod to be rolled. Arrows on the roller 4 and the rolling stock 5 show the respective rotational movement or progress movement of the roller 4 or of the rolling stock 5 at.

As the 2 clarifies, the eccentric bushing 1 facing surface 6 of the piezoelectric element 3 in a first drive state in contact with the eccentric bushing 1 to be brought. The 3 shows a second driving state of the piezoelectric element 3 , Here is the piezo element 3 with its surface 6 from the surface of the eccentric bush 1 moves.

The 4 clarifies that adjacent piezo elements 3 can be divided into two groups with regard to their activation. In the in 4 Operating situation shown are the piezo elements 3A currently contracted while the piezo elements 3B are currently elongated.

The elongated and the contracted operating state of the piezo elements 3 can be changed with high frequency. Because of the inertia of the eccentric bush 1 This can be the movement of the surface 6 the piezo elements 3 do not follow. This in turn causes the contact between the eccentric bushing 1 on the one hand and the respective surface 6 of the respective piezoelectric element 3 on the other hand, during a certain period of time each excitation cycle is canceled. There is no contact between the surface 6 of the piezoelectric element 3 and the surface of the eccentric bush 1 , so there can be no friction at this point. As a result, the friction can be reduced when the eccentric bushing 1 to be rotated within the warehouse. The use of two (or more) groups of piezoelectric elements 3 offers the advantage of always having a contact between the surface 6 given some piezo elements and the surface of the eccentric bush. As a result, the resulting from the rolling force normal force between the eccentric bushing on the one hand and with the piezoelectric elements 3 equipped storage unit on the other hand are transmitted optimally and without time interruption.

In 5 It is shown that in a preferred embodiment, the piezoelectric elements 3 only on one side of the eccentric bush 1 must be executed. This is the side of the eccentric bush which is pressed against the skeleton housing due to the normal force resulting from the rolling force. Furthermore, the shows 5 that the basic body 2 the bearing of the invention as a drawer 2a in a scaffold housing 7 a rolling mill according to the invention can be formed.

6 shows starting from the design of the 5 that two more slots 8th . 9 for the scaffold housing 7 the rolling mill according to the invention can be provided. The bays 8th . 9 between their respective bodies and the eccentric bush 1 arranged piezoelectric elements 10 . 11 on. These can be operated in the manner of a stepping drive and thereby a rotational movement of the eccentric bushing 1 relative to the framework housing 7 enable. For this purpose, the friction of the bearing of the eccentric bush 1 in the bearing according to the invention by appropriately driving the piezoelectric elements 3 reduced. During the period of reduced friction, the piezoelectric elements can 10 . 11 be driven as a stepping drive and the eccentric bushing 1 relative to the framework housing 7 rotate.

Claims (9)

Bearing for a roll neck of a roll of a roll stand or for a roll shaft or for a roll neck or the roll shaft supporting eccentric bush, characterized by a base body ( 2 ) and at least one in the body ( 2 ) for contact with the roll neck or the roll shaft or the eccentric bushing ( 1 ) arranged piezoelectric element ( 3 . 10 . 11 ). Bearing according to claim 1, characterized by a plurality of in the basic body ( 2 ) for contact with the roll neck or the roll shaft or the eccentric bushing ( 1 ) arranged piezoelectric elements ( 3 . 10 . 11 ). Bearing according to claim 2, characterized in that the piezoelectric elements ( 3 ) in two or more groups ( 3A . 3B ) and that the individual groups ( 3A . 3B ) with the same frequency, but with a time delay. Bearing according to claim 3, characterized in that adjacent piezoelectric elements ( 3 ) different groups ( 3A . 3B ). Bearing according to one of claims 1 to 4, characterized by piezoelectric elements ( 10 . 11 ), which are controlled as a stepping drive. Roll stand comprising at least one roller ( 4 ) Having at least one roll neck or a roll shaft, the / in a warehouse after one of claims 1 to 5 is stored. Roll stand comprising at least one roller ( 4 ) with a roll neck or at least one roll shaft, which in eccentric bushings ( 1 ) are rotatably mounted, characterized in that the eccentric bushing ( 1 ) rotatably via a bearing according to one of claims 1 to 5 in the housing ( 7 ) of the roll stand is mounted. Roll stand according to claim 6 or 7, characterized in that the bearing as a einschiebbarer in a receptacle of the housing of the roll stand, in the receptacle for receiving and forwarding forces to the housing ( 7 ) fixable insert ( 2a ; 8th ; 9 ) is trained. Method for radially setting the roll of a roll stand according to one of claims 7 or 8, characterized in that the piezoelectric elements ( 3 ) of the bearing are oscillated, so that the friction between the eccentric bushing ( 1 ) and reduces the roll neck and the roller is radially adjusted by rotation of the eccentric bushing.

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