Roll or roller – Rotatable relative to supporting shaft
Reexamination Certificate
2001-10-11
2003-12-16
Cuda-Rosenbaum, I (Department: 3726)
Roll or roller
Rotatable relative to supporting shaft
C492S007000, C492S020000, C492S002000
Reexamination Certificate
active
06663549
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 of German Patent Application No. 100 50 596.1, filed on Oct. 12, 2000, the disclosure of which is expressly incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The instant invention relates to a deflection controlled roll having a rotatable roll jacket and a rotationally fixed carrier arranged within the roll jacket. A hydraulic support element arrangement is positioned between the carrier and the roll jacket, and a closed bearing ring is provided in a respective end region of the roll jacket and is movable in a press plane relative to the carrier. A bearing arrangement is positioned between the bearing ring and the roll jacket.
2. Description of Related Art
Such a deflection controlled roll is known from, e.g., EP 0 332 549B 1. The roll jacket rotates around the rotationally fixedly supported carrier in operation. Deflections resulting on an appropriate loading of the roll jacket are absorbed by the hydraulic support element arrangement. This supports the roll jacket with respect to the carrier from the inside. While a deflection of the carrier can also occur here, the elastic line of the roll jacket can be appropriately better influenced.
The support element arrangement can, however, only absorb forces which act in a press plane extending through the press gap or nip formed with a counter surface. The relevant forces can therefore be produced, for example, by a counter-roll or a roll stack downstream thereof. In addition, the roll jacket must be held on the carrier by a bearing which permits a rotation of the roll jacket with respect to the carrier and simultaneously allows a certain jacket positioning.
The relevant bearing arrangement is now exposed to different loads in different situations. The roll jacket is supported by the hydrostatic support elements with respect to the carrier in operation. The bearing arrangement can thus be held practically free of support forces at least with a vertically aligned roll stack in which the support elements between the carrier and the roll jacket also produce a vertically aligned force component. The roll jacket's own weight and the forces applied by the other rolls and acting in the press direction are absorbed by the support elements between the roll jacket and the carrier. The bearing arrangement in this case serves practically exclusively for the positioning of the roll jacket with respect to the carrier. If, in contrast, the press nip of the roll stack is opened, then the weight of the roll jacket rests on the bearing arrangement. In this case, the bearing arrangement must be able to absorb the jacket weight, and indeed also with a rotating roll jacket. It must in all cases be ensured that the bearing arrangement runs with as little play as possible which may not exceed a pre-determined measure.
With the previously known deflection controlled rolls of the kind initially mentioned, the bearing is formed by roll bodies. Such roll bearings, however, now have the disadvantage that they no longer work with the required reliability with the rolls which run increasingly faster.
SUMMARY OF THE INVENTION
The invention present invention provides an improved deflection controlled roll of the kind initially mentioned which is safe and works reliably in particular also at higher operating speeds.
Accordingly, the invention includes a bearing arrangement having at least two hydrostatic support elements which are mutually spaced in the peripheral direction and of which at least one is movable relative to the carrier; and in that at least one force generating device, which acts generally radially in the press plane and radially penetrates the bearing ring, that is arranged between the carrier and the roll jacket.
It is possible due to this embodiment to operate a respective deflection controlled roll with a jacket stroke also at higher speeds, that is at peripheral speeds in the order of magnitude of, e.g., about 2,000 m/min. A defined support is possible in different radial directions by an appropriate distribution of the support elements associated with the bearing arrangement, with additional forces being able to be applied to the roll jacket in the bearing region via the force generating device penetrating the bearing ring. Since at least one, preferably more or even all support elements, can be movable with respect to the bearing ring, they are in a position to adjust themselves even with diameter changes of the roll jacket and/or of the bearing ring or of the carrier, which by no means have to develop in the same way, and thus to ensure that the roll jacket is always supported to the desired degree. Play such as is known from rolling bearings and which can result in an unfavorable vibration behavior in operation under certain circumstances, is kept extremely small with this kind of support. The hydrostatic support of the roll jacket in the region of the rotation bearings furthermore allows relatively low-wear operation, and indeed also at higher speeds.
While in a press roll known from, e.g., DE 29 42 002 C2, a support ring having hydrostatic support elements arranged at its periphery is already provided, this support ring is arranged in a middle roll region. Moreover, this support ring is stressed by force generating devices arranged between it and the carrier.
In a preferred practical embodiment of the deflection controlled roll of the invention, at least one hydrostatic support element each is provided at both sides of the press plane, with in particular at least two such support elements each being provided at each side.
It is also advantageous if at least some of the hydrostatic support elements are arranged pair-wise at mutually opposite bearing ring sides and the two support elements of each pair have mutually opposite radial directions of effect.
In a further appropriate embodiment of the deflection controlled roll of the invention, two force generating devices acting in opposite radial directions are provided on mutually opposite carrier sides.
Preferably at least one force generating device is formed by a respective hydraulic piston-in-cylinder arrangement.
The bearing ring is expediently rigidly designed. It is advantageously dimensioned such that a ring gap remains between the carrier and the bearing ring when these are in a mutually coaxial arrangement. As a consequence of the rigid, closed bearing ring, the forces occurring with any roll deformations are transferred via this ring from the one side to the other and from there again to the roll jacket without a support at the inner carrier occurring. A kind of expanding ring is formed by which the roll jacket is expanded. A support at the inner carrier should therefore not normally take place. A support of the bearing ring at the carrier can only take place with occurring tangential forces and tilt movements accompanying these and with other forces acting from the outside. Corresponding external forces can occur, for example, with a horizontal roll arrangement having overhead stabilizing elements which carry the roll weight and with the use of an external scraper, by which, however, only minor forces are produced.
In a preferred practical embodiment of the deflection controlled roll of the invention, the movable support element has a bearing pocket arrangement whose effective surface is larger than a surface of the support element onto which a pressure between the bearing ring and the support element is effective. It is thereby ensured that while the support element can be pressed into the bearing ring with a certain force when appropriate forces act on the roll jacket, the force with which the support element contacts the bearing ring is limited since hydraulic pressures build up above and beneath the support element. The magnitude of said force can be influenced by the surface difference. Thus, a stable support results even with changing diameters of the roll jacket. It is practically ensured that the roll jacket always
Cuda-Rosenbaum I
Voith Paper Patent GmbH
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