TM 5-3820-233-12/1
Table 4-3. V-Belt Deflection
"S" dimension in sixty-fourths. Example: The deflection
for a 100" span would be 100/64" or 1 9/16".
Deflection
Recommended deflection
(3) Hook spring scale at center of belt span and read
V-Belt location
distance
force in pounds
pounds required to deflect each belt "S" dimension.
per belt
(4) Consult table for belt used. If spring scale reads
Minimum
Maximum
between the two figures shown, the belt is properly
tensioned (fig. 4-51).
Countershaft to head
1 1/4 inch
14
20
pulley
(5) Refer to table 4-3 for proper V-belt deflection.
Countershaft to power
1 1/2 inch
14
20
unit
CAUTION
Power unit to jaw
1 inch
8
12
When making V-belt adjustments with
crusher
Crusher to feeder
1 1/4 inch
7
10
countershafts and/or power units, be
sure adjusting bolts are moved
(1) Measure shaft centers (in inches) dimension "T."
equally to maintain countershafts or
(2) Multiply "T" by 1/64" which will give deflection
power unit perpendicular to the plant
frame.
DEFLECTION
1/64" PER
INCH OF SPAN
Figure 4-51. Measuring V-belt deflection.
4-49
