Patent ID: 6419794
Filing Date: 2002-07-16
Classification: B65H,D21G

Abstract:
In a paper machine, an oscillation damping apparatus for damping oscillations of rotating rolls, said oscillation damping apparatus comprising:at least two rolls, two of said rolls defining a nip therebetween, each said roll having two opposite ends; a plurality of bearings, each said bearing holding a respective one of said opposite ends of said two rolls; means for pivoting at least one of said two rolls in at least one direction toward and away from said nip; at least one sensor associated with at least one of said two rolls, each said sensor detecting oscillation values of prevailing roll oscillations of at least one said roll; and at least one actuator configured for introducing at least one active stimulation phase-shifted counteroscillation from outside said rolls into at least one of said bearings based upon said oscillation values detected by at least one said sensor.