VALS MED MAGNETISKT KOMPENSERAD OCH/ELLER REGLERAD BOJNING

摘要

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.