Chain & V-Belt Tensioning
Roller chains are power transmission components with positive transmission which, by virtue of their design are subject, depending on quality, to elongation as a result of wear of 1 to 3% of their total length. Inspite of this elongation, due to aging, a roller chain transmits the occurring torques effectively providing it is periodically retensioned. Without tension adjustment, the slack side of the chain becomes steadiliy longer, ascillates and reduces the force transmitting wrap angle of the chain on the sprockets.
The chain no longer runs smoothly off the teeth of the sprockets, producing uneven running of the entire drive and supporting wear. The service life of the chain drive can be extended considerably by the use of an automatic chain tension adjuster. The tensioning element prevents the slack side of the chain from ‘sagging’ or ‘slapping’ by its automatic operation and very wide tensioning range for compensating this given elongation.
The tensioning element is based on the rubber spring principle. According to application it is supplemented with the appropriate idler sprocket for chain drives or with a belt roller pulley in belt tensioner applications.
Pre-tensioning
With the tensioning element the necessary travel and simultaneously the corresponding initial tension force can be accurately adjusted by a torsion angle scale and indicating arrow. Excessive initial pretensioning of the chain should be avoided in order to reduce the tensile force and surface pressure on the links.
Vibration Damping
The tensioning element, based on a system of rubber springs, absorbs considerably the chain vibration due to internal molecular friction in the rubber inserts. The rubber spring effectively absorbs the vibrations, resulting from the polygon effect, which also positively influences the noise level of the complete chain drive.