Method and equipment for attenuation of oscillation in a paper machine or in a paper finishing device
AssigneeMetso Paper, Inc.
InventorsJouko Karhunen, Arto Puranen, Jorma Köliö, Esa Lehtovirta, Erkki Hietamäki
Life of this patent
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Abstract
A method and apparatus for damping vibration in a paper machine. The apparatus having a dynamic damper which includes a weight suspended by a spring. The spring constant of the spring is changed by means of a control device in order to tune the natural frequency of the dynamic damper. The dynamic damper is tuned to a frequency that is substantially equal to a multiple of the rotational frequency of the roll in the paper machine that is being damped.
Claims26
A method for damping vibration induced by a roll (1) in a paper machine or in a paper finishing device by means of a dynamic damper which comprises:
- a weight (4, 4a, 4b) and a spring (3, 3a, 3b), connecting the weight (4, 4a, 4b) to a vibrating system (2) of the paper machine or paper finishing device, whereby the dynamic damper is tuned by means of a control device (9) to a tuning frequency that is substantially equal to a multiple of the rotational frequency of the roll (1) that is closest to the natural frequency of the vibrating system (2), or to a tuning frequency that substantially corresponds to the problematic excitation frequency of the vibrating system (2), wherein said weight (4, 4a, 4b) is suspended from said vibrating system by means of said spring (3, 3a, 3b) and in that, the spring constant of the spring (3, 3b) of the dynamic damper and/or the mass of the weight (4a, 4b) of the dynamic damper is/are changed by means of the control device (9) in order to tune the natural frequency of the dynamic damper so as to be said tuning frequency.
An apparatus for damping vibration induced by a roll (1) in a paper machine or in a paper finishing device, said apparatus having a dynamic damper which comprises a weight (4, 4a, 4b) and a spring (3, 3a, 3b) connecting the weight (4, 4a, 4b) to a vibrating system (2) of the paper machine or paper finishing device, said apparatus further comprising a control device which is arranged to tune the dynamic damper to a tuning frequency that is substantially equal to a multiple of the rotational frequency of the roll (1) that is closest to the natural frequency of the vibrating system, or to a frequency that substantially corresponds to the problematic excitation frequency of the vibrating system wherein said weight (4, 4a, 4b) is suspended from said vibrating system (2) by means of said spring (3, 3a, 3b) and in that said control device (9) is arranged to change the spring constant of the spring (3, 3b) of the dynamic damper and/or the mass of the weight (4a, 4b) of the dynamic damper in order to tune the natural frequency of the dynamic damper so as to be said tuning frequency.
Dependencies are inferred from the claim text.