DE20109015U1 - Leadership role - Google Patents

Description

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AB SKF Schweinfurt, 29. 5. 2001

DEOlOIlDE STP-go.ne

Description

Leadership role

The invention relates to a guide roller for guiding a wire to or from a work roll in a wire rolling mill, which has an outer shell with a profile for guiding the wire, which is rotatably mounted via rolling elements relative to a fixed inner ring.

When producing wire in a wire rolling mill, wire is first produced with a nominal starting thickness. The starting thickness is usually a multiple of the diameter that the finished wire is to have. The wire is therefore fed to a wire rolling mill. In this mill, several wire rolling stands are arranged in a row through which the wire is fed. In each wire rolling stand, at least two work rolls act on the wire, reducing its diameter. The exact guidance of the wire to and from the individual wire rolling stands is achieved by guide rollers, which have a profile on their outer circumference that is suitable for guiding the wire.

In known wire rolling mills, the guide rollers are located in front of and/or behind the individual wire rolling stands in the position in which the wire enters the wire rolling stand. This gradually occurs - from wire rolling stand to wire rolling stand - as the diameter of the wire

reduced, leads to an increase in the wire speed: The first wire rolling stands, viewed in the wire feed direction, roll the wire at a relatively low speed, while the speed increases from wire rolling stand to wire rolling stand. The last wire rolling stands receive the wire at an extremely high speed (up to 120 m per second) and roll the wire into its final shape at the corresponding speed.

While no problems arise in this regard in the continuous process - the individual guide rollers in the respective wire rolling stands simply rotate at their respective speeds - difficulties arise when a new wire to be rolled enters the wire rolling mill for the first time. While no problematic operation is observed in the front area of the mill at relatively low speeds, the wire enters the last wire rolling stands or the corresponding guide rollers at considerable speed, so that large load peaks are observed, particularly on the guide rollers. The wire approaching at high speed must accelerate the guide roller from its rest position to the corresponding speed when it hits it, which leads to high bearing loads. The outer surface of the guide roller in particular, but also the bearing of the guide roller, therefore wear out after a relatively short time, which makes frequent repairs necessary, which in turn leads to a temporary shutdown of the wire rolling mill.

The invention is therefore based on the object of further developing a guide roller of the type mentioned at the beginning in such a way that it is possible to operate the wire rolling mill in such a way that the roller sleeve and also the bearings of the guide rollers have a significantly increased service life and frequent repairs become unnecessary.

The solution to this problem by the invention is characterized in that the outer shell is simultaneously designed as the outer ring of the rolling bearing.

According to the invention, the focus is on moving away from the previously known design concept of the guide rollers - namely two-part design of the rotating part of the guide roller in the rolling bearing outer ring and the outer shell of the roller and the outer shell of the roller simultaneously forming the outer ring of the rolling bearing.

Preferably, the average thickness of the outer shell is designed to be small in order to obtain the lowest possible mass moment of inertia in relation to the other bearing dimensions. In particular, it is intended that the outer shell has a mass moment of inertia of a maximum of 80%, preferably a maximum of 70%, compared to an element designed with an outer shell and a separate rolling bearing outer ring.

The design according to the invention ensures that the rotating part of the guide roller has a significantly reduced moment of inertia compared to previously known rollers, which means that the wire entering between two stationary guide rollers causes a smaller impact, since less energy is required to accelerate the guide rollers to wire speed. This means that the roller shell and the roller bearing can be protected, which enables a longer service life.

The drawing shows an embodiment of the invention. The only figure shows two guide rollers, looking in the wire feed direction, of a wire rolling stand.

From the figure it can be seen that two guide rollers 1, one of which is shown in section, work together to guide the wire 2 passing through a wire rolling stand to two cooperating work rollers 3. The guide rollers 1

each have two axially spaced inner rings 6, which are provided with guide tracks for rolling elements 7. The rolling elements 7 simultaneously represent the connection to the outer shell 4, which is designed as the outer ring of the rolling bearing. On its radially outer surface, it has a profile 5, which is suitable for guiding the wire 2 through the guide roller 1.

The outer casing 4 therefore fulfils two functions: Firstly, it serves as the outer ring of the rolling bearing, and at the same time it serves as the rotating part of the guide roller, which guides the wire 2 in a targeted manner.

The drawing shows that the radial thickness of the outer casing d is relatively small in relation to the other dimensions of the guide roller. This ensures that the mass moment of inertia of the outer casing 4 is relatively low and lies significantly below the values that are usually observed in wire guide rollers for the two-part combination of rolling bearing outer ring and roller outer casing. Consequently, only a much lower energy is required to accelerate the wire 2 onto two stationary guide rollers 1 to a peripheral speed corresponding to the wire speed when it hits them. The roller casing and the bearing are therefore exposed to a much lower load than is the case with known guide rollers.

The design according to the invention makes it possible to reduce the mass moment of inertia of the rotating part of the guide rollers to a value of less than 70% - compared to previously known rollers.

The measures described ensure that when the wire enters between two guide rollers, there is less of an impact than is the case with rollers according to the state of the art. This means that the roller casing and the bearings of the guide rollers are treated more gently, so that the

Durability of the shells and bearings can be increased compared to previously known designs.

AB SKF Schweinfurt, 29. 5. 2001

DEOlOIlDE STP-go.ne

List of reference symbols

1 Leadership role 2 wire 3 Working roll 4 Outer jacket 5 Profiling 6 Inner ring 7 Rolling elements

Thickness of outer jacket

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Claims (3)

1. Guide roller ( 1 ) for guiding a wire ( 2 ) to or from a work roll ( 3 ) in a wire rolling mill,
which has an outer casing ( 4 ) with a profile ( 5 ) for guiding the wire ( 2 ) which is mounted on roller bearings relative to a fixed inner ring ( 6 ) via rolling elements ( 7 ),
characterized ,
that the outer shell ( 4 ) is simultaneously designed as the outer ring of the rolling bearing. 2. Guide roller according to claim 1, characterized in that the average thickness (d) of the outer casing ( 4 ) is designed to be small in order to obtain the lowest possible mass moment of inertia in relation to the other bearing dimensions. 3. Guide roller according to claim 2, characterized in that the outer casing ( 4 ) has a mass moment of inertia of a maximum of 80%, preferably a maximum of 70%, compared to an element formed with an outer casing and a separate rolling bearing outer ring.