TM 5-3820-233-12/2
3-17. Drive Belts
allow oil or grease to accumulate on them. Oil
a. Before Operation Inspection.
not only has a deteriorating effect on rubber,
(1) Wipe all parts of drive unit with a clean cloth.
but also causes slippage and will mix with rock,
(2) Inspect all belts for excessive wear or damage.
thus forming an abrasive compound that will
(3) Inspect wear on conveyor belt fasteners.
prematurely wear the belts and sheave grooves.
CAUTION
b. During Operation Inspection. Inspect all belts for
Do not use belt dressing on V-belts and do not
slippage. If slippage occurs stop unit and tighten belts.
Refer to Table 3-3 for proper V-belt deflection.
Table 3-3. V-Belt Deflection.
Recommended deflection
V-belt location
Defection distance
force in pounds
Minimum Maximum
Engine to main countershaft
1-1/16 inch
11
16
Main countershaft to lower countershaft
3/4 inch
11
16
Lower countershaft to sand conveyor speed reducer
1/2 inch
8
11
Lower countershaft to screen countershaft
1/2 inch
11
16
Screen countershaft to screen vibrating unit
1/4 inch
11
16
Lower countershaft to rock conveyor idler countershaft
7/8 inch
11
16
Rock conveyor idler countershaft to rock conveyor reducer
7/8 inch
8
11
Main countershaft to feed conveyor reducer
1/2 inch
11
16
Main countershaft to roll crusher flywheel
2 inch
11
16
Roll countershaft to elevating wheel countershaft
7/8 inch
11
16
.
3-18. Screen Alignrnent Gage Plate
The vibrating screen is equipped with a screen alignment
plate. To properly read this plate face the straight edge and
watch the pattern on gage plate (fig. 3-9).
a. If screen is operating correctly a half diamond shape
pattern will be visible and in line with straight edge while
operating as shown in figure 3-10A.
b. If under load, the pattern appears as in figure 3-10B,
the screen box is operating below center. To correct,
compress the coil springs equally, on both sides of box.
c. If above load, the pattern appears as in figure 3-10C,
the screen box is operating above center. To correct,
relieve tension of coil springs equally (fig. 4-68).
d. After the screen has been adjusted properly while
under normal load with equipment stopped, the screen box
will be setting above center when stopped empty as shown
on gage plate in figure 3-10 D.
NOTE
The final check should be made while screen is
operating with load under normal operating
conditions. Screen must be checked daily to
assure screen adjustment at all times.
Figure 3-9. Screen alignment gage plate.
3-15
