Airstream 1100 SERIES SINGLE FAN PNEG-339 - Manual (Page 31)

31
SERVICE
FAN PROPELLOR REMOVAL AND INSTALLATION
The fan propellor is secured to the
motor shaft by the use of a taper-
lock bushing, motor shaft key and
three cap screws.
CAUTION: Although the taper-lock
method of retaining the propellor
onto the motor shaft is simple, it is
essential that the following points be
read carefully and fully understood.
Improper installation can cause a
loose flying propellor, and result in
serious injury or death.
THREADED BUSHING
HOLES
The threaded holes within the bush-
ing are provided for disassembly
purposes only. Do not attempt to use
these holes for reassembly. They
will not allow the parts to lock onto
the shaft thereby causing a hazard-
ous operating condition.
CLEARANCE HOLES
Fan Hub
Key
Capscrews installed
through threaded
holes of bushing
2. REMOVE the three cap screws
from the clearance holes in the
taper-lock bushing.
3. INSTALL two grade 5 cap
screws into the threaded holes
in bushing. TURN caps by hand
until they bottom against the
front surface of the propellor.
4. BLOCK propellor to prevent it
from turning, and gradually TURN
the cap screws (up to 1/4 turn
at a time) until the propellor
breaks loose from the bushing
and motor shaft. Carefully RE-
MOVE bushing and propellor.
With the propellor free from the
bushing, a wheel can be used
to PULL the bushing off of the
motor shaft. REATTACH bush-
ing onto propellor to prevent the
loss of parts.
Note: During manufacture the
propellor and bushing on the 26" and
28" solid aluminum blades are bal-
anced together, and are marked with
two small dots to identify their origi-
nal alignment position. CHECK the
bushing and propellor to make
sure they have alignment marks.
MARK the alignment of the propellor
and bushing, if necessary.
Crowley blades have a keyway
to prevent any misalignment of the
propellor and bushing. Alignment
marks are on the back of the fan hub
assembly. To replace one of the
blade fins, alignment would be nec-
essary, however, this is not recom-
mended. In most cases, the com-
plete propellor should be changed.
Split Taper Bushing
Fan Hub
Fan blade
removal
Split Taper Bushing
Capscrews installed
through threaded
holes of bushing
When reassembling parts, the cap
screws must be installed through
the untapped clearance holes as
shown. This will cause the propellor
to be pulled forward onto the ta-
pered bushing, thus locking the
parts securely onto the motor shaft.
When fan servicing requires re-
moval and installation of the
propellor, make sure the propellor
is removed and reinstalled properly.
1. LOCK OUT the fan power
supply, and REMOVE the fan
guard and the venturi, as re-
quired on some models.
Fan blade
installation