Metal deforming – By use of roller or roller-like tool-element – Included in roller-cluster
Reexamination Certificate
2001-03-28
2002-12-10
Tolan, Ed (Department: 3725)
Metal deforming
By use of roller or roller-like tool-element
Included in roller-cluster
C072S235000, C072S237000
Reexamination Certificate
active
06490901
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rolling unit for a rolling mill for rolling or sizing metal pipes, bars or wires having at least three rolls arranged in a star-shaped arrangement around a rolling mill axis, each of which has a separate drive means and is rotatably mounted by means of a roll shaft and bearings arranged on both sides of each roll. Each roll is mounted in a rolling unit housing so that it is radially adjustable in the rolling unit housing.
2. Prior Art
A rolling unit of this type has already been disclosed in WO 98/06515. The rolls there are mounted in built-in components, with which they can be shifted in a radial direction relative to the rolling mill axis within the rolling unit housing. Devices for shifting and holding the built-in components and thus the rolls in a radial direction are arranged in a rolling unit frame, which surrounds the rolling unit housing. The drive units provided for driving the rolls are located outside of the rolling unit frame.
This sort of rolling unit has the disadvantage that its outer dimensions are comparatively large and a considerable amount of space is required for the entire rolling mill. This results, above all, from the arrangement and structure of the adjusting devices for radially adjusting and holding the built-in components. These adjusting devices require much space in a radial direction. Space is required for pre-tensioning means for producing tension arranged between the built-in components and devices for radial adjustment. Thus when no rolled goods are being rolled, there is no plays between these parts. Consequently particularly large outer dimensions are required for the rolling unit frame supporting these devices and the rolling unit housing. The rolling unit frame and the rolling unit housing are of course separate parts in the known structure, but they form a functional unit and form an especially large complete rolling unit only together with the radially adjustable rolls. Since the drive units for the rolls are arranged outside of the rolling unit frame, considerable spacing of the drive units from the roll mill axis exists and thus the rolling mill has considerable dimensions in a radial direction. However the known rolling unit also has a great width in the axial direction, i.e. in the direction of the rolling mill axis, because the built-in components are held in place by swivel pins, which are arranged laterally next to the rolling unit housing. Because of that a large spacing of the rolling units and thus also of the calibrated openings formed by the rolls from each other results, which has the consequence that the length of the unusable thicker end section of the rolled goods is considerably large. Also the waste during production is large.
Furthermore manufacturing expenses are especially high for the known rolling unit, because of the use of built-in components and devices for holding, guiding and radially adjusting the built-in components, which must be made with numerous individual parts and assembled.
Furthermore the known rolling unit has a weak structure because of the numerous individual parts, which give way too much to the forces occurring during rolling. The known rolling unit thus does not maintain the rolls in their provided positions with sufficient accuracy and reliability continuously in the required manner under the currently common high loads produced by the forces on the rolls. Because of that the required narrow tolerances for the rolled goods are not maintained. The flexibility of the known structure toward the forces acting on the rolls is based, above all, on the fact that the built-in components are only held in the structure by swivel pins. Furthermore the forces are conducted through several individual parts and thus over a comparatively long distance, which leads to a comparatively large elastic deformation. Furthermore exact adjustment of the rolls is impaired by wear, which is to be expected in the region of the operating surfaces between the linearly moving devices for radial adjustment of the built-in components and the built-in components that are pivotable on a circular path. Primarily there is a danger that these operating surfaces are temporarily exposed to dirt or dust when the rolling unit housing is removed.
An additional disadvantage of the known rolling unit is that the diameter of the opening formed by the rolls cannot be adjusted and measured when the rolling unit housing is in the workshop. This is because in the workshop the built-in components take arbitrary positions in the rolling unit housing and these can always be changed. In the workshop the built-in components and the rolls are guided of course in a radial direction in the rolling unit housing, however are fixed in no position. The devices for radial adjusting and holding the built-in components and rolls are missing. As already mentioned, these devices are arranged in the rolling unit frame, which is fast attached in the rolling mill, thus they cannot be transported together with the rolling unit housing in the workshop. However when the rolling unit housing is again inserted in the rolling unit frame and thus in the rolling mill, the devices for radial adjustment and holding can operate again. Then the built-in components and the rolls take certain adjustable positions relative to the rolling mill axis. However the position of the rolls and thus the diameter of the opening between them is then not measured in most rolling units, because its rolling unit housing is inside the rolling unit frame. Then the rolls are arranged close to each other in the rolling mill so that only the opening between them in the first and last rolling unit can be reached and measured. Even if the opening between the rolls could be adjusted to the same diameter with special devices in the workshop as it is when adjusted by the devices for radial adjustment and holding of the built-in components and rolls in the rolling mill, this would still not be sufficient if the average position of the rolling unit housing relative to these special devices in the workshop and to the devices for radial adjustment and retention of the built-in components in the rolling mill is not maintained equal or the same with extreme accuracy. Each deviation even with constant diameter of the roll openings leads to an axially incorrect position of the rolls and thus necessarily to sizing errors.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a rolling unit for a rolling mill for rolling or sizing metal pipes, bars and wires, which does not have the above-described disadvantages, but which allows a stable, but radially adjustable position of the rolls with as small as possible dimensions and comparatively small manufacturing expense.
These objects, and others that will be made more apparent hereinafter, are attained in a rolling unit having at least three rolls arranged in a star configuration or arrangement around the rolling mill axis, each of which has a separate drive means and is rotatably mounted by means of a roll shaft and bearings arranged on both sides of each roll. Each roll is mounted in a rolling unit housing so that it is radially adjustable in the rolling unit housing.
According to the invention this object is attained by a rolling unit of this type in which the bearings for the roll shafts are roller bearings and they are located within eccentric sleeves which are arranged rotatably in bearing passages of a closed one-piece rolling unit housing and in which an adjusting device for continuously changing the rotational position of the eccentric sleeves and a retaining device for holding them fixed in a predetermined rotational position are provided.
The rolling unit according to the invention has a very compact structure with only very small outer dimensions. That is due to the fact that the devices for adjusting and maintaining the rolls comprise eccentric sleeves. The eccentric sleeves, in contrast to the known built-in components, and the devices
Kocks Technik GmH & Co.
Striker Michael J.
Tolan Ed
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