H&S GM 170, Operator'S Manual And Parts List

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MILL/BLOWER DRIVE
The combination mill/blower driven sheave is connected from the main drive sheave by an 8" “A” section
banded drive belt. Adjusting bolts are provided to align the drive sheave with the driven sheave as well as
to adjust the drive belt tension.
ADJUSTMENTS
Sheave Alignment
To align the combination mill/blower driven sheave with the driven sheave, proceed as follows:
1. Loosen both of the bolt/nut (A & B) assemblies on the main drive shaft.
2. Place a straightedge across the faces of both sheaves (C & D) to check alignment.
3. Adjust the nut on the left bolt assembly (A) and the bolt on the right side assembly (B) to bring
the drive sheave into alignment with the driven sheave.
4. After proper alignment is obtained, check and adjust drive belt tension.
Belt Tension
To adjust mill/blower drive belt tension, proceed as follows:
1. Check the drive belt tension initially by measuring the amount of belt deflection at the
midway point between the sheaves while applying a 60 lb. of force at the midway point.
2. Adjust the nut on the left bolt assembly (A) clockwise to decrease deflection (increase tension)
and adjust the right side bolt assembly (B) an equal number of turns counterclockwise to keep
drive sheave in alignment with driven sheave. Adjust both sides until the deflection measures
3/8" (10 mm).
3. After proper tension is obtained, check for correct sheave alignment, retighten the lock nut on the
right side bolt.
-27-
NOTE: A new drive belt should be adjusted for an initial tension of 3/8" (10 mm) deflection with an
applied pressure of 80 lb. (360 N). Refer to the Service chapter of this manual for new belt installation
procedures.
B A
C
D