Patent ID: 7914430
Filing Date: 2011-03-29
Classification: D21G,F16C

Abstract:
1. A roll in a paper, board or finishing machine comprising: an inner shell defining an axis direction, having a middle, and made of a first material having a first density, and a first modulus of elasticity in the axial direction, and a first nominal stiffness defined as the first modulus of elasticity in the axial direction divided by the first density of 0.055 to 0.165 Gnm/kg; wherein the inner shell of the roll has two ends which are supported by inner bearings at the ends of the inner shell; an outer shell having a middle and made of a second material having a second density, and a second modulus of elasticity in the axial direction, and a second nominal stiffness defined as the second modulus of elasticity in the axial direction divided by the second density of 0.035 to 0.055 GNm/kg, the inner shell middle and the outer shell middle in supporting engagement, the outer shell being in direct supporting engagement with the inner shell only about the inner shell middle; wherein the outer shell of the roll has two ends which are supported by outer bearings at the ends of the outer shell, so that vibration of the ends of the outer shell is controlled; and wherein the first modulus of elasticity in the axial direction is 2-4 times the second modulus of elasticity in the axial direction.