Brandt GRAIN VAC 5000, Руководство оператора и каталог запасных частей

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48
5.15.1 If the Fan is Rubbing
1. Open the upper body by opening the two latches and swinging the lid open.
2. With the vac disconnected from the
power source, feel the clearance
between the fan rotor and the inlet
tube. There should be a gap of
approximately 1/2” between the fan
rotor and the inlet tube. See Fig. 38.
3. If the gap between the fan rotor and
the metal seal flange is less than 1/2”,
the fan rotor or the bearing box and
rotor have slid back in the housing. To
determine which, inspect the fan
tapered bushing. If the bushing is flush
with the end of the shaft, the bearing
box has moved. if the bushing is not
flush, the Fan Rotor has moved.
4. If the bearing box has moved, loosen
the six mounting bolts and use the three
adjusting bolts to move the bearing box. See Fig. 37. Move the bearing box so the gap between the
fan rotor and the metal seal flange is 1/2” evenly spaced all around. See Fig. 38. Tighten the six
mounting bolts to at least 80 ft.lbs. Test by turning the vac slowly and listening for the fan rubbing on
the inlet. If no rubbing is heard, the problem has been corrected and the vac can be used.
5. If the fan tapered bushing is not flush with the end of the shaft, then the fan itself has slid back on the
bearing box shaft. To fix this, remove two of the three bolts in the fan mounting bushing and back the
third out until it is slightly engaged in the threads on the fan. Loosen the set screw in the bushing over
the key on the shaft. Install the two bolts that were removed into the threaded holes on the bushing and
use them to push the fan off the bushing. When the fan is loose, use a hammer and a punch to knock
the bushing back on the shaft until it is flush with the end of the shaft. Remove the two bolts that were
used to push the fan off the bushing and reinstall them into the holes in the bushing that are in line with
the threaded holes on the fan. The third bolt that was left in the fan and bushing should act as an
alignment for the other two bolts. Tighten the three bolts to 22 ft.lbs torque. This torque setting is
extremely important to prevent the fan from slipping again. Re-tighten the set screw over the key.
6. If the gap between the fan rotor and the inlet tube is uneven, the bearing box may have moved and
allowed the fan to tip inside the housing. To check this, remove the tension on the fan drive belt and
check the squareness of the two drive pulleys by using a long straight edge. If the pulleys are out of
square, the bearing box has moved. Loosen the six 1/2” mounting bolts holding the bearing box. Then,
by turning the 1/2” adjustment bolts, move the bearing box so there is an even gap between the fan
rotor and the inlet tube which in turn will square the two pulleys. Re-tighten the six mounting bolts and
torque the nuts to at least 80 ft.lbs. Recheck the alignment of the pulleys. Adjust if necessary.
F
IG
. 38 A
DJUSTING THE
F
AN IN THE
H
OUSING