Farm Fans C-2120A Operator's Manual page 48

sure propeller is removed and installed properly. The
recommended procedure is as follows:
REMOVAL
1. LOCK OUT THE MAIN POWER SUPPLY and remove
the fan guard, and also the venturi, as required on
some models of equipment.
2. Remove the three capscrews from the clearance holes
in taper-lock bushing. Inspect for thread damage and
set capscrews aside for later reinstallation (do not use
these bolts for step 3, bushing removal).
3. Install three GRADE 5 CAPSCREWS into the
THREADED HOLES in the bushing and turn them in by
hand until they bottom against the front surface of the
propeller. These capscrews should not be used for
reassembly, as some thread distortion could occur dur-
ing the removal operation. Grade 5 screws are marked
with three 120° spokes on the head and are more
durable than low strength unmarked bolts (see Fig. 7-5
for bolt identification).
NOTE: Early type bushings have only two threaded
holes, whereas the current type have three holes to
provide a more uniform pushing force. Do not attempt
to use low strength (unmarked) bolts to remove the
bushing, as the bolts may break off. This is espe-
cially important for the early two-hole type bushing
which provides off-center forcing action.
4. Block propeller to prevent it from turning, and gradual-
ly turn in the capscrews (up to 1/4 turn at time), as
shown in Fig. 7-5, until the propeller breaks loose from
the bushing and motor shaft. Carefully remove bush-
ing and propeller. With the propeller free from the
bushing, a wheel puller can be used to pull the bushing
off of motor shaft, if required. Reattach bushing onto
propeller to prevent the loss of parts and also to main-
tain the original bushing/propeller alignment. Inspect
propeller and bushing at this time, looking for any
cracks, thread or bolt damage, warpage, etc. Consult
your dealer or the factory for any questions concerning
damage.
NOTE: During manufacture, the propeller and bush-
ing are balanced together and the parts are marked
with two small punch dots to identify their original align-
ment position (propeller hub punch dots are near bush-
ing keyway). Observe bushing and propeller to make
sure they have alignment marks. Mark the alignment
of the propeller and bushing, if required.
INSTALLATION
1. Carefully clean the motor shaft, key, bushing and bore
of propeller. Make sure main power is locked out, and
that shaft and key are completely free of rust and burrs.
Do NOT lubricate the bushing or capscrews. Check
and make sure all motor mount bolts are properly
tightened.
2. Before installing the propeller, check the following: (1)
If any balance weights are installed, they must be tight-
ly secured. (2) All foreign material must be removed
from the propeller, especially inside the hub area. (3)
Carefully inspect the propeller casting for damage,
cracks or other defects. Contact the factory if there is
any question regarding the structural integrity of the
propeller casting.
PROP.DS4
Fig. 7-4 Cutaway of typical propeller installation
PROP.DS4
Fig. 7-5 Capscrew arrangement for disassembly
PROP.DS4
Fig. 7-6 Capscrew arrangement for reassembly
46
PROPELLER
TAPER-LOCK
BUSHING
CAPSCREWS
THREADED HOLES
IN BUSHING
PROPELLER
TAPER-LOCK
BUSHING
CAPSCREWS INSTALLED INTO
THREADED HOLES TO FORCE
PROPELLER OFF BUSHING
PROPELLER
TAPER-LOCK
BUSHING
CAPSCREWS INSTALLED THROUGH
CLEARANCE HOLES OF BUSHING
(See text for proper torque)
KEY
GRADE 5
CAPSCREW
KEY