Pressure roll for use in calenders and the like

Abstract

A pressure roll for use in calenders has a fixed carrier for a hollow cylindrical shell which is rotatable about and is movable radially of the carrier. The position of the shell relative to the carrier and the positions of longitudinal increments of the shell relative to each other are regulated by one or more supporting devices each of which has a row of neighboring hydrostatic bearing elements having convex surfaces with pockets adjacent the internal surface of the shell and being urged against the shell by discrete cylinder and piston units, one for each bearing element. Each bearing element has an elongated elliptical or rectangular outline and has a width in the circumferential direction of the shell which greatly exceeds its length in the axial direction of the shell. Each cylinder and piston unit has a piston whose cross-sectional outline equals or approximates that of the respective bearing element and which is only slightly smaller than the respective bearing element. The pistons are mounted on the carrier and extend into complementary cylinder chambers in the adjacent inner sides of the respective bearing elements. The cylinder and piston units can receive a heated hydraulic fluid at a controlled pressure. The relatively wide but short pistons ensure that the bearing elements can stand large deforming stresses.