Arrangement for belt control

Abstract

An arrangement for handling a paper, cardboard, tissue or other fibrous-material web in a machine for producing and/or finishing the same, includes an endlessly circulating belt of high flexural rigidity which wraps around a rotatably mounted control roller with an angle of wrap, wherein at least one end of the control roller is displaceably mounted along an adjusting zone for setting the belt tension. The arrangement of the present invention provides an improved running of the belt and the lateral stress of the belt is minimized by the angle of wrap lying between 90° and 180° and the adjusting direction of the control roller lying approximately perpendicular to the bisector of the angle of wrap.

1 . An arrangement for treating a fibrous web in a machine for at least one of producing and finishing the fibrous web, the arrangement comprising:
 a control roll having at least one rotatably mounted end; and   an endlessly circulating belt having a high flexural rigidity and being wrapped around said control roll forming a wrap angle having a bisector, said wrap angle lying between approximately 90° and 180°; and   wherein said control roll is configured to be mounted so as to be displaceable along an adjusting travel in an adjusting direction to set a tension of said endlessly circulating belt, said adjusting direction lying approximately perpendicular to said bisector of said wrap angle.   
   
   
       2 . The arrangement of  claim 1 , wherein an angle between said adjusting direction and said bisector of said wrap angle lies between approximately 60° and 120°. 
   
   
       3 . The arrangement of  claim 1 , wherein an angle between said adjusting direction and said bisector of said wrap angle lies between approximately 80° and 100°. 
   
   
       4 . The arrangement of  claim 1 , wherein an angle between said adjusting direction and said bisector of said wrap angle lies between approximately 85° and 95°. 
   
   
       5 . The arrangement of  claim 1 , wherein said adjusting travel has a maximum length of approximately 60 mm. 
   
   
       6 . The arrangement of  claim 1 , the control roll further comprising a first bearing and a second bearing, said first bearing being adjusted. 
   
   
       7 . The arrangement of  claim 6 , wherein said first bearing and said second bearing are adjusted. 
   
   
       8 . The arrangement of  claim 7 , wherein said first bearing and said second bearing are adjusted in opposite directions. 
   
   
       9 . The arrangement of  claim 1 , wherein said belt has a modulus of elasticity greater than 100 kN/mm 2 . 
   
   
       10 . The arrangement of  claim 1 , wherein said belt has a modulus of elasticity greater than 190 kN/mm 2 . 
   
   
       11 . The arrangement of  claim 1 , wherein the width of said belt is greater than 2 m. 
   
   
       12 . The arrangement of  claim 1 , wherein the thickness of said belt is greater than 0.5 mm. 
   
   
       13 . The arrangement of  claim 1 , wherein the thickness of said belt is greater than 0.8 mm. 
   
   
       14 . The arrangement of  claim 1 , wherein said belt is a steel belt. 
   
   
       15 . The arrangement of  claim 1 , wherein said belt is impermeable. 
   
   
       16 . The arrangement of  claim 1 , further comprising:
 a pressure element;   a supporting element running with said belt; and   at least one functional belt; and   wherein said belt is configured to be pressed by said pressure element against said supporting element, the fibrous web running one of on its own and with said at least one functional belt between said supporting element and said belt.   
   
   
       17 . The arrangement of  claim 16 , wherein said pressure element is a stationary pressure chamber fillable with a pressurized fluid, said pressure chamber being configured to be open to said belt and sealed off from said belt. 
   
   
       18 . The arrangement of  claim 16 , wherein said supporting element is a rotating supporting roll. 
   
   
       19 . The arrangement of  claim 18 , wherein said control roll is arranged before said supporting roll relative to a travel direction of said belt. 
   
   
       20 . The arrangement of  claim 19 , wherein said belt has an overall length, said belt extending from said control roll to said supporting roll having a length along said belt, said length along said belt being less than one-third of said overall length. 
   
   
       21 . The arrangement of  claim 20 , wherein said belt has an overall length, said belt extending from said control roll to said supporting roll having a length along said belt, said length along said belt being less than one-quarter of said overall length. 
   
   
       22 . The arrangement of  claim 1 , further comprising a roll cover. 
   
   
       23 . The arrangement of  claim 22 , wherein said roll cover is rubber. 
   
   
       24 . The arrangement of  claim 22 , wherein said roll cover has a friction μ greater than 0.2. 
   
   
       25 . The arrangement of  claim 22 , wherein said roll cover has grooves. 
   
   
       26 . The arrangement of  claim 25 , wherein said grooves run one of axially parallel and with a herringbone geometry.