33
Adjusting Belt Tension
Proper belt tension and pulley alignment must be maintained for maximum
drive efficiency and for maximum belt life. The correct tensions exists if a
deflection of ½ inch occurs by placing 10lbs of force midway between
the motor pulley and the compressor flywheel. This deflection can be ad-
justed by the following procedure. The pulley should be carefully aligned
with the flywheel and set screws should be kept tight.
1. Remove the belt guard.
2. Loosen the motor mounting
bolts.
3. Shift the motor to the point
where the correct deflection
exists.
4. Retighten the motor
mounting belts.
5. Check to ensure that the ten-
sion remain correct after tightening.
6. Re-install the belt guard. All moving parts must be guarded.
NOTE: Drive belt tension and pulley alignment are done at the
same time. They are discussed separately for clarity.
Pulley Alignment
The figure to the side shows 3 examples of misaligned pulleys. To check
pulley alignment, remove the belt guard and place a straightedge against
the compressor flywheel, measure and record the distance from the
straightedge to the edge of the drive belt. Then measure the distance to
the edge of the drive belt on the motor pulley at the same edge. As long
as both points measure the same distance the pulleys will be aligned if
not you will need to move the pulley until its in alignment this may take a
few tries. To re-align the pulley follow the
steps below.
1. Loosen the motor mounting bolts.
2. Remove the belt guard.
3. Loosen the set screw on the motor
pulley.
4. Align the motor pulley with the
compressor flywheel.
5. Re-tighten the motor pulley set screws.
6. Adjust the proper belt tension.
7. Re-tighten the motor mounting bolts.
8. Re-install the belt guard.
adjustments & alignment
ANGULAR
MISALIGNMENT
PARALLEL
MISALIGNMENT
PULLEY GROOVE
AXIAL
MISALIGNMENT
PUMP
FLYWHEEL
STRAIGHT EDGE
MOTOR
PULLY
DRIVE
BELT
EDGE
DRIVE
BELT
EDGE
A
B
C
