USC U-Batch, Operator'S Manual

Page: 58 / 118

Page 58
U-BATCH™ TREATER
Belt Tensioning Specification
Section
H
Synchronous Belts
High torque, Standard and Metric synchronous belts should be installed to fit pulleys
snugly, neither too tight nor too loose. The belts positive grip eliminates the need for
high initial tension. When a belt is installed with a snug but not overly tight fit, longer
belt life, less bearing wear and more quiet operation will result. Over tight belts may
cause early failure and should be avoided. With high torque a loose belt may “jump
teeth” upon startup. If this occurs, the tension should be increased gradually until
satisfactory operation is achieved.
To properly tension a synchronous belt, place belt on pulleys and adjust take up until
the belt teeth mesh securely with the pulley grooves. Measure belt span “T”. Then
tighten belt so it deflects 1/64-inch for every inch of belt span when a force as specified
in the table below is applied to the top of the belt. For belts wider than two inches, a
metal or wooden strip 3/4 to 1 inch wide should be placed across the belt between
it and the tester to prevent distortion.
The following range of deflection forces are normally adequate for a used drive belt.
BELT PITCH BELT WIDTH DEFLECTION FORCE
POLY CHAIN
SYNCHRONOUS
8MM 8.0 to 8.8 lbs
POLY CHAIN
SYNCHRONOUS
14MM 25 to 27 lbs