1. Field of the Invention
The invention relates to a suction roll for the formation or treatment of a material web, such as, in particular, a paper, card or textile web. The suction roll includes an outer suction roll jacket formed by a perforated, rotating, hollow cylinder and a non-perforated support body which passes through the suction roll jacket. The suction roll jacket is supported on the support body, at at least one point of its axial extent, in particular against its own weight, against the suction force, against the tensile force of an outer, recirculating belt, and/or against a pressing force acting from the outside.
2. Discussion of Background Information
The previously known suction rolls of this kind have, among other things, the disadvantage that the line force is restricted to a relatively low value. These rolls are thus, for example, not suitable for use in connection with deflection compensated rolls.
In a suction roll of the initially named kind known from DE-C-227223 in which a plurality of longitudinal cells subjected to axial suction are formed between a screen-like perforated outer jacket and an inner jacket, the inner jacket is secured by spiders and hubs to a rotating shaft.
In FR-A-2364291 a roll subjected to suction from the outside is described which includes a hollow, deflection compensated cylinder which is supported via a sliding shoe on an inner stationary carrier, which has through-going radial bores with a relatively large spacing from one another which communicate with longitudinal grooves. The roll is also provided with an outer jacket having longitudinal grooves which communicate with those of the deflection compensated cylinder, and thus with the inner space of the deflection compensated cylinder. In another embodiment of a roll subjected to suction from the outside, known from this FR-A-236429 1, a non-perforated roll jacket provided with grooves is supported via a pressure medium chamber on an inner stationary carrier.