TM 5-3820-233-12/2
belt sag between troughing rolls. Belt sag should not
4-50. Belt Tension Adjustment
exceed 1/2 to 3/4 inch between trough roll assemblies
The conveyor is equipped with an adjustable tail pulley to
spaced on 4 foot centers (1% sag considered normal).
maintain the necessary belt tension.
a. Back off lock nuts on adjusting bolts and turn the
NOTE
two adjusting nuts the same number of turns (fig. 4-39).
When installed conveyor belt is to stand idle
b. Tighten until proper belt tension is obtained to
during seasonal weather change, loosen belt
prevent slippage and eliminate most of the
to allow for contraction.
Figure 4-39. Conveyor belt adjustment.
4-51. Belt Training
A slight adjustment of troughing and return rolls can
centrally on conveyor.
d. To adjust under side of conveyor belt not running
quickly correct belt travel over rolls and pulleys on the
conveyor (fig. 4-40).
in center of tail pulley or return rolls, proceed as follows:
a. Square the adjustable head pulley and tail pulley
(1) Taking reverse direction of belt travel into
with the frame.
consideration loosen end of return roll and move toward
b. Square troughing and return rolls.
tail pulley to cause creep to other side of conveyor.
c. Start the conveyor and run belt empty at reduced
(2) Correct one roll assembly at a time until belt
is centered.
speed. Check belt travel over rolls and head and tail
e. Adjustment may be necessary after the belt is
pulley and adjust troughing rolls where belt starts to run
operating at normal load.
off center as follows:
f. Belt creep to one side consistently in one localized
(1) Loosen troughing roll clamp on side of
area, requires adjustment of troughing or return rolls at
conveyor belt that it is shifting toward.
that point.
(2) Move end of troughing roll forward toward
g. Belt repair can be accomplished using belt
head pulley.
(3) Make slight adjustment and check one or two
fasteners when a slight tear or fraying occurs to prevent
complete revolutions of conveyor.
further damage to the belt as shown in figure 4-41.
(4) Adjust rolls as required until belt runs
4-34
