Dynapac PL 500/20 S, Operation & Maintenance Manual

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F 42
F PL
500/
20S.
G
B 42
-74
- 04.
07
3.5 Loading unit
Belt tension
$
Check belt tension on the upper convey-
or on a daily basis. If there is too much
slack in the belt, adjust the tension.
During the first weeks of operation, the
belt may stretch excessively (residual
and elastic elongation).
It is therefore necessary to adjust the
belt tension repeatedly during this peri-
od.
Increasing the tension:
- Unfasten lock nuts (1) on both sides of
the clamping fixtures.
- Adjust tension on both sides evenly on the adjusting nuts (2) using an open-end
wrench.
- Tighten lock nuts (1) back down after the adjustment procedure.
If the belt on the reversing drum is running to one side, tighten the right-hand spindle
or loosen the left-hand spindle if the drum is rotating clockwise, or vice versa for an-
ticlockwise rotation.
$
Avoid excessive angle setting on the reversing drum because this can cause the belt
fabric to stretch excessively.
If the reversing roller is unable to apply sufficient tension control, the load-bearing roll-
ers need to be realigned. To do this, unfasten the displacement plate for the load-
bearing station and twist the station round slightly.
If the belt is to be adjusted to the right, the left-hand load-bearing roller needs to be
pushed forwards, or its right-hand side needs to be pushed forwards if the belt needs
to be adjusted towards the left side.
The following factors can cause the belt to run at an oblique angle:
- Encrusted material on drums and rollers.
- Off-centre material build-up
- Differing levels of belt stretch, e.g. one-sided over-tightening
- One-sided wear of the drum friction lining
- Chafing of belt against machine frame.
- Improper version of endless belt connection.
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