EP1501643B1 - Device and method for mounting a roll ring onto a shaft of a rolling stand - Google Patents

Abstract

A roll ring (22) is rotationally fixed onto a shaft (20) in a roll ring arrangement (22). Said shaft comprises a threaded area (30) and a fixing area (32) which is disposed respectively in an axial manner next to the cylinder ring. A screw nut (36) is screwed onto the screw area, exerting a high axial working tension on the roll ring, said tension being sufficiently high in order to transfer the rotational torque required for a rolling process between the shaft and the roll ring. A hydraulically operating clamping device (50) is fixed in a detachable manner to the securing area and can exert a high axial working tension on the roll ring independently and alternatively from the screw-nut. A radially positioning unit is actuated independently from the axial clamping device and the screw-nut. Said unit comprises a centering means and is embodied in such a manner that radial backlash between the shaft and the roll ring is eliminated by the centering means (34). The invention also relates to a method for clamping a roll ring in said type of roll ring arrangement.

Description

The invention relates to a rolling ring assembly according to the preamble of claim 1 and a method for tensioning a rolling ring on a shaft in such a rolling ring assembly.

Such a rolling ring assembly and such a method are out GB 1583 711 A known.

Out US 4,650,364 If a rolling ring arrangement is previously known, in which a rolling ring is fixed essentially by radial tension, the radial tension is chosen to be sufficiently high for the transmission of a torque required for a rolling operation between shaft and rolling ring. In such rolling ring arrangements of the rolling ring is relatively heavily stressed to train. Although modern rolling rings hold high pressure forces, but are not very tensile, this applies z. B. made of hard metal rolling rings.

It has therefore been for some time to a substantial axial clamping of the rolling ring passed.

To show EP 343440 B and DE 201 08 915 U Rolling ring assemblies in which the rolling ring is clamped by axial working tension substantially. For centering in the radial direction, a ring cone is provided. This is actuated by the same single hydraulic tensioner, which is also responsible for the axial tension. An independent radial clamping or alignment and axial clamping is not possible. It is also not possible to remove the hydraulic clamping tool after the application of the working voltage from the shaft and use, for example, for another rolling ring assembly. Continue on DE 3 834 606 A directed.

This is where the invention begins. It has set itself the task of developing a rolling ring arrangement to the effect that the axial clamping is independent of the radial positioning and that the axial clamping device, which is preferably located in a clamping tool, can be removed from the shaft when the clamping operation is terminated ,

This object is achieved by the features of claim 1.

In this rolling ring arrangement, the necessary for a clamping operation, high axial operating voltage can alternatively be applied by the nut screwed onto the threaded portion or by the hydraulically operating, axial clamping device. Both work independently of each other. The nut can be rotated or actuated independently of the axial clamping device, the axial clamping device operates independently of the mother. The axial clamping device is intended to perform the clamping operation and the release operation. The nut is designed to maintain the working tension achieved hydraulically.

This makes it possible to remove the axial tensioning device from the shaft as soon as the axial working tension is transmitted through the nut.

Furthermore, the radial positioning is independent of the axial clamping. The rolling ring can be centered by means of the radial positioning unit without the axial tension having to be changed or changed.

The rolling ring assembly thus enables an axial tensioning device formed in a tightening tool to be sequentially used for a plurality of rolling ring assemblies during tensioning and relaxing. The achieved axial tension is maintained by the nut, which is a relatively simple mechanical component. It must therefore not be provided an expensive hydraulic working axial clamping tool for each rolling ring assembly.

Since the radial positioning unit operates independently of the two components responsible for the axial tension, namely the nut and the hydraulically operating axial clamping device, the radial positioning can be carried out selectively and carefully. The force exerted on the rolling rings radial force can be dosed very accurately and targeted. An excessive radial stress, which would reduce the life of the rolling rings, can be prevented. Rather, the radial stress can be kept so low that only a positioning takes place without the rolling ring is noticeably stretched radially. It is therefore deliberately spoken of a radial positioning and axial clamping in the context of the present application.

The invention also relates to a method for tensioning a rolling ring on a shaft of a roll stand using the rolling ring arrangement, as described above. It is the object of the invention to provide a method for tensioning a rolling ring of a shaft, in which as little as possible controllable radial forces are exerted on the rolling ring during clamping and independently of this a high axial tension necessary for the transmission of a torque during the rolling process can be applied.

• die Welle einen Gewindebereich und einen Befestigungsbereich aufweist, die sich beide neben dem Walzring befinden,
• eine Mutter vorgesehen ist, die auf den Gewindebereich aufgeschraubt ist und die eine hohe axiale Arbeitsspannung auf den Walzring ausüben kann, welche ausreichend groß ist für eine Übertragung eines für einen Walzvorgang nötigen Drehmomentes zwischen Welle und Walzring,
• eine hydraulisch arbeitende, axiale Spannvorrichtung vorgesehen ist, die lösbar am Befestigungsbereich angeordnet ist und die unabhängig von der Mutter und alternativ zur Mutter die hohe axiale Arbeitsspannung auf den Walzring ausüben kann und
• eine radiale Positioniereinheit vorgesehen ist, die
  1. a) unabhängig von der Mutter und der axialen Spannvorrichtung betätigbar ist
  2. b) ein zwischen Walzring und Welle befindliches Zentriermittel aufweist und
  3. c) so ausgelegt ist, dass durch das Zentriermittel jegliches radial Spiel zwischen Welle und Walzring eliminiert ist,

bei welchem Verfahren ein Spannvorgang des Walzrings auf der Welle wie folgt abläuft:

• die radiale Positioniereinheit wird so betrieben, dass ein radiales Spiel zwischen Welle und Walzring eliminiert wird,
• die axiale Spannvorrichtung wird so betrieben, dass die hohe axiale Arbeitsspannung zwischen Welle und Walzring aufgebracht wird,
• danach wird die Mutter auf dem Gewindebereich so gegen den Walzring gedreht, dass sie am Walzring anliegt und die axiale Spannvorrichtung wird entspannt und vom Befestigungsbereich entfernt.

This object is achieved by a method for tensioning a rolling ring on a shaft of a roll stand, wherein

• the shaft has a threaded portion and a mounting portion, both located adjacent to the rolling ring,
• a nut is provided which is screwed onto the threaded portion and which can exert a high axial working tension on the rolling ring, which is sufficiently large for a transmission of a torque required for a rolling operation between shaft and rolling ring,
• a hydraulically-operating, axial clamping device is provided, which is detachably arranged on the fastening region and which can exert the high axial operating stress on the rolling ring, independently of the nut and, alternatively, to the nut, and
• a radial positioning unit is provided which
  1. a) is actuated independently of the nut and the axial clamping device
  2. b) has a located between rolling ring and shaft centering and
  3. c) is designed so that any radial clearance between the shaft and rolling ring is eliminated by the centering,

In which method a clamping operation of the rolling ring on the shaft proceeds as follows:

• the radial positioning unit is operated in such a way that radial play between the shaft and rolling ring is eliminated,
• the axial tensioning device is operated in such a way that the high axial working tension is applied between the shaft and the rolling ring,
• Thereafter, the nut is rotated on the threaded portion against the rolling ring, that it rests against the rolling ring and the axial tensioning device is relaxed and removed from the mounting area.

Since the mother as well as the axial clamping device is able to exert an exclusively axial clamping force on the rolling ring, after the successful clamping, which must be done hydraulically, and tightening the nut against the rolling ring, the hydraulic voltage can be switched off and the clamping device can be removed. The axial tension is then maintained by the nut. Completely independent of this, the radial positioning takes place by means of the radial positioning unit. The latter is only operated so that the radial stresses on the rolling ring remain within the permitted limits, but sufficient radial positioning or centering of the rolling ring is achieved.

In a particularly preferred embodiment of the method according to the invention, it has proven to be advantageous according to the features of claim 14 to proceed stepwise. For example, initially a certain radial positioning is performed with the first radial positioning force. Thereafter, an axial clamping takes place with a first axial tension. Now the radial positioning is performed again, it is increased to a second positioning force. Anschleißend the axial clamping device is actuated to a second axial voltage. These operations are carried out until the required high axial working voltage is reached and the radial positioning has taken place. It is also possible to start with the axial clamping and then to position only radially. The initial axial stress must be chosen so low that a radial positioning remains possible.

In a preferred embodiment, after reaching the high axial operating voltage, the radial positioning unit is released, for example, relaxed. The radial positioning of the rolling ring, when once the high axial operating voltage is applied, no longer change, because the rolling ring is fixed by the high axial working voltage.

Even if the high axial operating voltage is applied, it is still advantageous to leave the centering of the radial positioning in place, so not to remove. In principle, it is possible to remove this centering. But it is better to leave it in its place, to have as little air between rolling ring and shaft as possible.

In a further improvement, it is proposed that the radial positioning unit operates hydraulically and has an expandable hydraulic pressure chamber system which does not communicate with the hydraulically operating axial tensioning device. The radial positioning has its own drive, which is preferably designed hydraulically. It is basically possible to form this drive also otherwise, so for example mechanical, pneumatic or the like.

In a further improvement, it is proposed that the centering means have a ring cone. A rigid centering has proved to be favorable. In principle, it is also possible to otherwise form the centering means itself, for example to carry out hydraulically. Thus, it is possible to use a radially inflatable hollow ring as a centering, the cavity can be pressurized with hydraulic fluid. As an advantageous embodiment of the radial positioning unit, a combination of a centering cone and an axially acting, hydraulic pressure chamber system has proven.

In a preferred embodiment, a clamping tool is provided, which receives at least the axial clamping device, but preferably also accommodates an axially operating hydraulic pressure chamber system of the radial positioning unit. In a further development, it is advantageous to provide the nut with bores running parallel to the axial direction and insert a pin into each bore, which pin is displaceably arranged in the bore and designed for pressure transmission between the hydraulic pressure chamber system of the radial positioning unit and a ring cone , The slopes of the ring cone are preferably chosen so that it is self-locking. Once the radial positioning has taken place, the ring cone no longer needs to be actively held by the hydraulic pressure chamber system. Rather, this can be removed, which is done by removing the clamping tool in which the axial clamping device is located.

As a centering a radially expandable sleeve is advantageous. This can, as has already been pointed out, work hydraulically; it can also work otherwise, for example by axial force acting on the sleeve, expanding radially. Such a sleeve can be used in place of the ring cone mentioned above.

In a preferred embodiment, the attachment area has a smaller outer diameter than the inner diameter of the thread of the nut. It is then possible, when attaching or removing the nut, to rotate it only over the threaded area, while the nut can be pushed over the mounting area. This simplifies assembly.

It is basically possible to carry out fastening area and threaded area as sections of a uniform continuous thread. However, a division into a threaded area and a mounting area has Advantages. The threaded area can be designed as a fine thread. The attachment region can be designed so that rapid assembly and disassembly of the clamping tool is possible, it can be designed, for example, as a bayonet connection, as Schnellschraubverbindung etc .. In a further improvement .It is provided that the hydraulically operating, axial clamping device comprises a support means, the nut radially and axially overlaps and has the window for a rotation of the nut, preferably, the support means is designed as a support sleeve or a plurality of support pins. The two axial clamping means, namely the nut and the axial clamping device, are arranged axially next to one another. They both act on the same side surface of the rolling ring, albeit on different faces of the side surface of the rolling ring, or an intermediate support ring or the like. The support means transmits radially outside the nut, the clamping force of the axial clamping device on the rolling ring. The support means may be of any desired design, for example a ring with windows, an arrangement of pins, etc. Through the windows, rotation of the nut is possible without the support means having to be actuated.

In a preferred embodiment, the nut has a threaded portion adapted to the female thread and is located between the nut thread and rolling ring an axial clearance. This axial clearance is preferably greater than the diameter of the threaded portion. The axial clearance acts at least as part of an axial spring. It is stretched by the axial clamping device. The axial spring pulls the nut against the rolling ring after tensioning. During the normal rolling process is no hydraulic voltage to the rolling ring assembly, but the clamping tool is removed. The high axial working voltage is maintained solely by mechanical means. This means that only small masses are in the rolling ring arrangement. The clamping tool can be used for other rolling ring arrangements.

It is understood that the invention preferably relates to shafts with free shaft end.

Figur 1:

Ein axiales Schnittbild einer Walzringanordnung eines (hier nicht näher dargestellten, da ansich bekannten) Walzgerüstes, mit einer Ölspanntasche als Zentriermittel,

Figur 2:

eine Darstellung wie Figur 1, jedoch nunmehr mh bewei Konushülsen als Zentriermittel und einem Spannwerkzeug, das eine axiale Spannvorrichtung und ein hydraulisches Druckkammersystem einer radialen Positioniereinheit aufnimmt,

Figur 3:

eine Darstellung wie Figur 2, jedoch nunmehr mit einer mechanisch expandierbaren Zylinderbuchse als Zentriermittel,

Figur 4:

eine Darstellung ähnlich Figur 3 eines vierten Ausführungsbeispieles, bei dem das Zentriermittel nunmehr eine Konushülse ist und

Figur 5:

eine Darstellung des vierten Ausführungsbeispieles nach Figur 4 in der Ausführung für normalen Betriebszustand des Walzes, also mit Übertragung der hohen axialen Arbeitspannung durch eine Mutter, abgenommenem Spannwerkzeug und mit einer Schutzkappe.

Further advantages and features of the invention will become apparent from the other claims and the following description of non-limiting embodiments of the invention, which are explained below with reference to the accompanying drawings. In this drawing show:

FIG. 1:

An axial sectional view of a rolling ring arrangement of a (not shown here, as known ansich known) rolling stand, with an oil retaining pocket as a centering,

FIG. 2:

a representation as Figure 1, but now mh bewei conical sleeves as centering and a clamping tool that receives an axial clamping device and a hydraulic pressure chamber system of a radial positioning unit,

FIG. 3:

FIG. 2 shows a representation like FIG. 2, but now with a mechanically expandable cylinder bushing as a centering means;

FIG. 4:

a representation similar to Figure 3 of a fourth embodiment, wherein the centering means is now a conical sleeve and

FIG. 5:

a representation of the fourth embodiment of Figure 4 in the embodiment for normal operating condition of the roller, so with transmission of the high axial operating voltage by a mother, removed clamping tool and with a protective cap.

Figure 1 shows a first embodiment of the rolling ring assembly, in this embodiment, the individual features and functions are explained. The other three embodiments according to Figures 2, 3 and 4 including 5 will be explained with reference to the statements to the first embodiment only to the extent necessary for the description of the changes or deviations. In all embodiments, functionally identical, in particular identical components carry the same reference numerals.

The invention preferably relates to end-mounted rolling ring arrangements, but in principle can also be applied to two-sided rolling ring arrangements.

The rolling ring assembly according to the first embodiment has a rolling ring 22 made of hard metal, which has 2 grooves in the embodiment shown here. He is for the production of long material, z. As wire, designed. The arrangement further has a shaft 20, of which only one (left) end region is shown. The shaft 20 has a collar on which the rolling ring 22 is supported to the right. Interposed is a sealing arrangement 24, it is known ansich, they need not be discussed in detail here.

Starting from its shaft collar and towards the left, free end, the shaft 20 initially has a receiving region 26 for the rolling ring, a free region 28, a threaded region 30 and a fastening region 32. The rolling ring is located radially outside the receiving region 26, which is here is made substantially cylindrical. Between receiving area 26 and rolling ring 22, a centering means 34 is arranged, which is designed here as an oil retaining pocket. The centering means 34 may be controlled and radially expanded depending on other actuators to be described.

The free area 28 serves as a spring together with optionally other portions of the shaft 20, this will be discussed later.

The threaded portion 30 is designed as a fine thread, with him a thread of a nut 36 is engaged. This has the shape of a pot in the embodiments, but this form is not mandatory. It is crucial that the nut 36 including the threaded portion 30 is designed so that it can exert on the left side surface of the rolling ring 22 a high axial working tension, which is sufficiently large for a transmission of a torque required for a rolling torque between shaft 20 and rolling ring 22nd It is possible to provide on the side surface 38 an intermediate ring, support ring or the like, so that the right end face of the nut 36 does not bear directly on the rolling ring 22.

The nut 36 finally has puncture openings 40 on its outer shell. They are distributed so that the nut 36 can be rotated comfortably. Other means of attack for a turning tool z. B. polygonal, toothing or a mechanical rotating device for the nut 36, for example by means of a driven toothed belt, are possible.

The attachment region 32 is provided for a clamping tool 42, which has a holding region 44 cooperating with the attachment region 32.

Although it is in principle possible to perform threaded portion 30 and mounting portion 32 throughout in one embodiment, for example, as a thread. However, it is preferable to adapt the threaded area 30 concretely to the requirements of the nut 36, in particular as a fine thread, and to design the fastening area in such a way that the clamping tool 42 can be quickly pushed onto the mounting area 32 or otherwise mounted thereon. For this purpose are suitable as a mounting area 32 and holding portion 44, for example Aufsteckgewinde, bayonet, coarse thread and the like.

In a preferred embodiment, however, which is not shown in the figures, the outer diameter of the mounting portion 32 is smaller than the inner diameter of the nut 36. Thus, the nut 36, once it has been unscrewed from the threaded portion 30, are pulled over the mounting portion 32. This facilitates handling, in particular assembly of the device.

Radially outside the nut 36 is a support means 46 which has substantially the shape of an annular sleeve. The support means 46 has windows 48, which are located in the region of the insertion openings 40. The support means 46 is arranged between the clamping tool 42 and the rolling ring 22. It abuts another partial surface of the side surface 38 on the rolling ring 22 as the right end surface of the nut 36. Via the support means 46, an axial stress is applied to the rolling ring 22.

In the clamping tool, a hydraulically operating, axial clamping device is provided. It has a hydraulic working space 52. The holding area 44 is provided on a stationary part 54. Opposite this is a cylinder 56 in the axial direction 58 hydraulically movable. The support means 46 abuts against the right end surface of the cylinder 56. If the working space 52 filled with hydraulic fluid, the cylinder 56 presses the support means 46 against the rolling ring 22, so that it is axially tensioned.

It can be seen that axial tensioning of the rolling ring 22 can take place either through the nut 36 and / or through the axial tensioning device 50. In practical operation, the axial clamping device 50 of the clamping tool 42 is used only for clamping and loosening. The tensioned state is maintained by the nut 36, as Figure 5 shows.

Finally, a radial positioning unit 60 is provided, of which a section, namely the centering means 34, has already been mentioned. Basically, the radial positioning unit 60 consists of a centering means and an actuating means which actively performs the controlled radial expansion or movement of the centering means. This actuating means, also called drive, is designed hydraulically in the embodiment of Figure 1. In the shaft 20, an oil hole is made, which consists of an axial bore and a radial bore that hits them. The radial bore opens into an expandable hydraulic pressure chamber system 64 of the radial positioning unit 60, this pressure chamber system 64 is provided in the embodiment of Figure 1 in the centering means 34. This has an outer annular disc, which expands upon filling of the pressure chamber system 64 with hydraulic fluid to the outside and therefore can form a radial force on the rolling ring 22. This force is preferably used only for radial centering or positioning, but not for radial clamping.

It can be seen that the radial positioning is completely independent of the axial stress and can be carried out.

A tightening process is as follows: First, the parts as shown in Figure 1, mounted. The rolling ring 22 is neither radially centered nor axially tensioned. By means of the radial positioning unit 60, a certain positioning is carried out, namely the centering means 34 is acted upon hydraulically with a first positioning force. As a result, a game between Walring 20 and shaft 20 is eliminated in the radial direction, at least reduced.

Next, the axial clamping device 50 of the clamping tool 42 is now actuated, the piston 56 is axially advanced to the right. This is done an axial tensioning with a first axial tension. This is still below the later required, high axial working voltage.

There is now a new positioning with a second positioning force to eliminate intervening game, in particular by the axial clamping occurred game, in particular radial play.

Thereafter, the axial tensioning device 50 is actuated again, now with a second axial tension, which is higher than the first axial tension.

The operations are continued until the axial tensioning device 50 tensions so strongly that the high axial working tension necessary for the rolling process is reached. It is also possible to set a higher voltage than the high axial working voltage, because when transferring the axial clamping state to the nut 36, it is not possible to transfer or maintain the complete hydraulically achieved axial tension.

Due to the hydraulically performed axial clamping process, a portion of the shaft 20 has stretched, this part belongs to the free area 28. In him is the high axial working voltage before. The nut 36, which had been initially loosely turned at the beginning of the clamping operation on the side surface 38 of the rolling ring 22, has now removed by the dimension A of this side surface 38. The length of the free end of the shaft was L before the tightening process, after the tightening it is L + ΔL.

The nut 36 is then again rotated so far against the rolling ring 22 that it rests against this. She has thereby obtained the opportunity to take over the axial stress. It can now be relaxed, the axial clamping device 50, so the piston are moved back. This can be done for example by positive emptying, for example, suction, the hydraulic fluid from the working chamber 52. Now it is the mother 36 who the high axial working tension on the rolling ring 22 exerts. The clamping tool 42 and the support means 46 can be removed. The pressure in the pressure chamber system 64 is maintained because a check valve is provided in the oil hole 62. It can be released by a pin.

It is possible to keep the radial positioning unit taut. It is also possible to switch off the pressure in the pressure chamber system 64.

Finally, a protective cap 66 is attached to the free shaft end, as shown in FIG. 5. Fig. 5, however, refers to another centering means, which should be clearly stated here. The protective cap bears against the side face 38 of the rolling ring 22 with a seal. It seals the entire end region beyond the rolling ring 22.

It may be advantageous to secure the nut 36 against inadvertent reverse rotation by means of a suitable locking device, for example a lock nut.

This completes the clamping process. The rolling ring assembly in the condition shown in Fig. 5 can now be used for practical rolling operations. If the rolling ring 22 worn, or you want to dismantle for other reasons, the clamping tool 42 is again recognized. An axial tension is exerted on the roller ring 22 by means of the axial tensioning device 50 and transmitted by the support means 46, which is so great that it is possible to rotate the nut 36 freely. In addition, the radial positioning unit 60 is relaxed, if not already done. The clamping tool 42 can now be removed. Also, the mother can be removed. The rolling ring 22 can be removed.

The above-described sequence of the tensioning process or the subsequent expansion is only an example, although a preferred method. It is not necessary to proceed step by step, it is also possible to simultaneously position radially and tension it axially. It is also possible to start during the clamping operation with the axial clamping at a low axial clamping force and then to position radially with a smaller positioning force. It is only crucial that a good radial positioning is achieved, in which there is no play against the shaft over the entire contact surface of the rolling ring. The axial stress must be high enough to maintain the high axial working stress required for the rolling operation over the entire useful life of the nut by means of the nut 36 and associated parts.

In the following, the second to fourth embodiments will now be discussed.

In the exemplary embodiment according to FIG. 2, the centering means 34 is a ring cone to which a further inner annular cone 68 is associated in opposite directions. The actuating means of the radial positioning unit 60 is now provided in the clamping tool 42. For this purpose, the pressure chamber system 64 is provided in the stationary part 64, to him an annular piston 70. The nut 36 has a number of axially parallel bores 72, which are formed for example as passages and preferably evenly distributed on a cylinder. In each passage 72, a pin 74 is housed, which is freely displaceable in the axial direction. The preferably identical pins 74 serve to transmit an axial positioning force from the annular piston 70 on the left side surface of the centering means designed as a ring cone 34th This left side surface lies in a radial plane, so has no gradations or the like. The angles of the two annular cone parts 34, 68 are in the range of self-locking. This makes it possible not to maintain a once achieved radial positioning during the normal rolling operation to have to. It is quite conceivable and advantageous to fix the centering means 34 in the achieved positioning position, for example mechanically. This can be done for example on specially designed pins 74, for example, the passages 72 are designed as threaded holes and the pins 74 are replaced by threaded pins. Other mechanical fixations are possible.

The embodiment of FIG. 2 has the advantage that both the axial clamping device 50 and the actuating means of the radial positioning unit 60 are formed in a clamping tool 42. Furthermore, there are only solid body between rolling ring 22 and shaft 20.

The embodiment according to FIG. 3 differs from the exemplary embodiment according to FIG. 2 in that the centering means is now a radially expandable sleeve, which can be radially expanded via axially introduced forces. There are again provided pins 74, as they can be found in the embodiment of FIG. 2.

In the embodiment of FIG. 4, in contrast to the embodiment of FIG. 2, no inner separate annular cone 68 is provided, but this is formed by the shaft itself.

The support means 46 now has a spy window 76 or more thereof. These windows are recesses on the right side surface of the support means 46 so that there is no continuous investment here. Through the at least one spy window 76, it is possible to recognize that the nut 36 actually rests against the rolling ring 22.

On the also belonging to the fourth embodiment Fig. 5 has already been noted. It shows the steady state in use.

In a modification of the second to fourth embodiments, it is also possible to provide the pressure chamber system in the cylinder 56. Then, although this moves back and forth with the axial movement of the cylinder 56 and is thereby given some interaction between axial clamping and radial positioning. However, these movements can be completely decoupled if the hydraulic control takes place accordingly. Thus, an exclusive axial clamping can take place in that the piston 56 is advanced axially to the right, but the same extent the annular piston 70 is retracted, thereby no actuation of the centering means 34th

Claims (15)

1. A roll ring assembly with

   - a roll ring (22),

   - a shaft (20) on which said roll ring (22) is non-rotatably disposed and which comprises a threaded portion (30) and a fastening portion (32) that are located axially beside the roll ring (22),

   - a nut (36) screwed on the threaded portion (30), said nut exerting onto said roll ring (22) an axial working tension high enough to transmit a torque needed for rolling between shaft (20) and roll ring (22),

   - a hydraulically operated axial fixture (50) that is releasably secured to the fastening portion (32) and that is capable of exerting the high axial working tension onto the roll ring (22) independent of the nut (36) and as an alternative thereto and

   - a radial positioning unit (60) having a centering means (34) and being devised in such a manner that any radial play between shaft (20) and roll ring (22) is eliminated through its centering means (34),

   characterized in that the radial positioning unit (60) is actuatable independent of the axial fixture (50) and of the nut (36).
2. The roll ring assembly as set forth in claim 1, characterized in that the nut (36) is located axially between the roll ring (22) and the axial fixture (50).
3. The roll ring assembly as set forth in claim 1, characterized in that the radial positioning unit (60) is operated hydraulically and has an expandable hydraulic pressure chamber system (64) that does not communicate with the hydraulically operated axial fixture (50).
4. The roll ring assembly as set forth in claim 1, characterized in that the centering means (34) has an annular cone.
5. The roll ring assembly as set forth in claim 3 and 4, characterized in that the expandable hydraulic pressure chamber system (64) of the radial positioning unit is located in a chuck (42) also receiving the axial fixture (50) and that the nut (36) has holes (62) extending parallel to the axial direction (58), a pin (74) devised for pressure transmission between the hydraulic pressure chamber system (64) and the annular cone being slidably disposed in each of said holes.
6. The roll ring assembly as set forth in claim 1, characterized in that the centering means (34) is a radially expandable bushing preferably having a hydraulically expandable pressure chamber.
7. The roll ring assembly as set forth in claim 1, characterized in that the fastening portion (32) has a smaller outer diameter than the inner diameter of the thread of the nut (36) and that both said fastening portion (32) and the threaded portion (30) are parts of a continuous external threading.
8. The roll ring assembly as set forth in claim 1, characterized in that the hydraulically operated axial fixture (50) is housed in a chuck (42) that a) has a holding portion (44) complementary to the fastening portion (32), that b) forms a hydraulic work space (52) for the fixture, that c) is releasably connected to the shaft (20) and that d) preferably also receives a hydraulically implemented, expandable pressure chamber of the radial positioning unit.
9. The roll ring assembly as set forth in claim 1, characterized in that the hydraulically operated axial fixture (50) has an abutment means (46) that forms a free partial grip around the nut (36) in the radial direction and has the window (48) for rotating the nut (36), said abutment means (46) being preferably configured to be an abutment sleeve or a plurality of abutment pins.
10. The roll ring assembly as set forth in claim 1, characterized in that the roll ring (22) has a first abutment surface at which it comes into contact with the nut (36) and that said roll ring (22) has a second abutment surface at which it comes into contact with the axial fixture.
11. The roll ring assembly as set forth in claim 1, characterized in that the nut (36) has a nut thread fitting the threaded portion (30) and that there is an axial space between nut thread and roll ring (22), which is preferably larger than one third of the diameter of the threaded portion (30).
12. The roll ring assembly as set forth in claim 1, characterized in that there is provided a protection cap (66) adapted to be placed onto a free end of the shaft (20) and that preferably has a seal by which it abuts the roll ring (22).
13. A method of fixing a roll ring (22) onto a shaft (20) of a roll stand,

    - said shaft (20) having a threaded portion (30) and a fastening portion (32) that are both located axially beside the roll ring (22),

    - a nut (36) being provided, which is screwed onto the threaded portion (30) and that is capable of exerting onto the roll ring (22) a high axial working tension that is high enough to transmit a torque needed for rolling between shaft (20) and roll ring (22),

    - a hydraulically operated axial fixture (50) that is releasably disposed on the fastening portion (32) and that is capable of exerting the high axial working tension onto the roll ring (22) independent of the nut (36) and as an alternative to said nut (36) being provided and

    - a radial positioning unit (60) being provided, which

    d) is actuatable independent of the nut (36) and the axial fixture

    e) has a centering means (34) located between roll ring (22) and shaft (20) and

    f) is devised in such a manner that any radial play between shaft (20) and roll ring (22) is eliminated by the centering means (34),

    by which method the roll ring (22) is fixed onto the shaft (20) in the following manner:

    - the radial positioning unit (60) is operated so as to eliminate any radial play between shaft (20) and roll ring (22),

    - the axial fixture (50) is operated so as to apply the high axial working tension between shaft (20) and roll ring (22),

    - the nut (36) is then rotated on the threaded portion (30) in such a manner against the roll ring (22) that it abuts said roll ring (22) and the axial fixture (50) is released and removed from the fastening portion (32).
14. A method as set forth in claim 13, characterized in that the radial positioning unit (60) and the axial fixture (50) are repeatedly operated consecutively or simultaneously, it being preferred that

    a) at first, a first radial positioning occur by means of the radial positioning unit at a first positioning force and a radial play between shaft (20) and roll ring (22) being thereby at least significantly reduced and the achieved first positioning force being maintained,

    b) a first axial tension, which is lower than the high axial working tension, be exerted onto the roll ring (22) by means of the axial fixture,

    c) the radial positioning unit be brought to a second positioning force that is higher than the first positioning force, a radial play being further reduced, more specifically a radial play appearing in step b) being reduced, with the achieved second positioning force being maintained,

    d) the axial fixture (50) is brought to a second axial tension that is higher than the first axial tension and

    e) repeating the steps until the high axial tension of the axial fixture is achieved.
15. The method as set forth in claim 13, characterized in that the radial positioning unit (60) is released once the high axial tension is achieved.

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