AAON M2-036 - Manual (Page 75)

75
Table 15 - Bearing Setscrew Torque
Recommendations
Shaft Size
(inches)
Setscrew Locking
Thread
Torque
(in-lbs.)
1 1/4 - 28 66 - 85
1 3/16 1/4 - 28 66 - 85
1 7/16 5/16 - 24 126 - 164
1 7/8 3/8 - 24 228 - 296
Shaft Size
(inch)
Skewzloc Locking
Thread
Torque
(in-lbs.)
1 8 - 32 63 - 70
1 3/16 8 - 32 63 - 70
1 7/16 10 - 24 81 - 90
1 7/8 1/4 - 20 162 - 180
Belts
Belt drive misalignment is one of the most
common causes of premature belt failure. A
belt can be destroyed in a matter of days if
the drives have been aligned incorrectly.
The most common tool for measuring
misalignment is a straightedge. Hold the
straightedge flush across one pulley to gauge
the degree of misalignment of the two
sheaves. The maximum allowed
misalignment is one half degree of angular
misalignment, and 1/10
th of an inch per foot
between sheave centers for parallel
misalignment.
Figure 28 - Angular Misalignment
Correct by moving the position of the motor.
Figure 29 - Parallel Misalignment
Correct by adjusting sheaves on one, or both
shafts.
Frequent belt tensioning is highly
recommended. Most belt manufacturers
would suggest a re-tensioning after as little
as 8 hours of operation. A simplified
method of adjusting tension is to gauge the
amount of force required to deflect the belt
by 1/64
th of an inch per inch of distance
between sheave centers. For example, if the
sheaves are 20 inches apart, then the amount
of deflection with the forces listed below is
20/64
th (5/16 th ) of an inch.
Deflection required for
“A” belts: 4-6 lbs.
“B” belts: 6-10 lbs.
“C” belts: 10-18 lbs.
Figure 30 - Belt Deflection
Sheave Centers
Force
Deflection = 1/64 th in.
per inch of length
Straightedge
Pulley
Pulley
Belt
Straightedge
Pulley Pulley
Belt