Abstract: An apparatus for the inductive heating of a roll used in the manufacture of paper by means of eddy currents, such as the inductive heating of a calender roll. In the apparatus, pole shoe devices provided with electromagnetic coils are used, by means of which the eddy-current heating is applied only to the surface layer of the roll, the surface layer being constituted of ferromagnetic material, solely from outside the roll. The apparatus comprises several iron cores placed side by side and provided with magnetizing coils. Into each coil, a magnetizing current is passed, the magnetizing current being of adjustable intensity and/or frequency to control the temperature profile of the roll in the axial direction thereof.

Abstract: A method and apparatus for the inductive heating of a roll used in the manufacture of paper by means of eddy currents, such as the inductive heating of a calender roll. In the apparatus, pole shoe devices provided with electromagnetic coils are used, by means of which the eddy-current heating is applied only to the surface layer of the roll, the surface layer being constituted of ferromagnetic material, solely from outside the roll. The apparatus comprises several iron cores placed side by side and provided with magnetizing coils. Into each coil, a magnetizing current is passed, the magnetizing current being of adjustable intensity and/or frequency to control the temperature profile of the roll in the axial direction thereof.

Abstract: A roller used as a press or calender roller in a paper machine is compensated for deflection and end-loaded. The roller has a stationary axle with spaced opposite ends at which the roller is loaded and a cylindrical shell rotatably mounted on the axle. The axle has a magnetic core portion within the shell having pole shoes spaced from the shell by air gaps and magnetizing coils of electrical conductors thereon at corresponding ones of the pole shoes. The coils produce a magnetomotive force and are positioned in a manner whereby magnetic flux passing through the air gaps between the pole shoes and the shell creates a compensating force field between the shell and the magnetic core. The roller has an inner part of the shell consisting of a stack of sheets of magnetically well-conductive material separated from each other by electrical insulation thereby reducing eddy current losses.

Abstract: A roller, magnetically compensated and adjusted for deflection, has a non-rotating axle with ends having a load imposed thereat and a cylindrical shell rotatably supported by bearings on the axle. A magnetic core is formed in the axle and has in transverse section a plurality of pole shoes spaced from the shell by an air gap. A plurality of electromagnetic windings, each wound on the core at a corresponding one of the pole shoes, produce a magnetic force in a manner whereby the magnetic flux through the air gap between the pole shoes and the shell produces a compensating force field between the shell and the core.

Abstract: A deflection-compensated roll of the type which is adapted to be used in the calender or press section of a paper machine. The roll has an inner non-rotating axle and an outer shell surrounding and rotatable with respect to the axle, this axle and shell having a common axis. The axle includes an inner magnet structure while the shell includes an outer magnet structure which rotates together with the shell. These inner and outer magnet structures cooperate to provide attraction between the shell and axle on one side of the above axis and repulsion between the shell and axle on the opposite side of the above axis, to achieve in this way a deflection-compensation.