7
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17
7.21 Roller Chain Tension and Replacement
Roller chains need to be tightened when they are worn or when they jump sprocket teeth.
Each chain has a certain amount of allowable chain movement. To measure the chain movement,
hold a tape measure up to the chain, then pull the chain down and then up. (The total amount of
movement in the chain should fit the specifications listed within the following sections.) When ser-
vicing or replacing roller chains, reset the chain to factory specifications.
Check the alignment of the sprockets periodically during the sea-
son and whenever replacing roller chains. To check alignment, lay
a straight edge along a machined surface of the sprockets. If there
is any misalignment, adjust the sprocket. For sprockets on a shaft
with end float, align the sprocket for the normal operating posi-
tion.
Install the replacement chain around both sprockets, bringing the
free ends together on one sprocket. Insert a connector link and
secure in place.
IMPORTANT:
Check chain tension after an initial 5 hours of operation.
7.21.1 Paddle Shaft Chain:
Paddle Shaft Chain has 1 ½ to 2 inches (3.8
-
5.1 cm) of allowable chain movement, as
shown in Figure 61.
Figure 7
-
32: Allowable Chain Movement
Figure 7
-
33: Paddle Shaft Chain Tension
Summary of Contents for 2720
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