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Donaldson Company, Inc.
Split Taper™ Bushing Mounting Instructions
Many fans are furnished with split taper bushings for
mounting the impeller to the shaft. When properly
assembled, the bushings grip the hub with a positive
clamping action.
1. Bushel barrel and bore of impeller are tapered to
ensure concentric mounting and a true running
propeller.
2. Capscrews, when tightened, lock bushing in
propeller. Use special plated capscrews and nylock
nuts.
Bushing No.
Bolt Size
Torque Ft-Lbs
QT/QH/L/H
1/4-20
7-1/2
3. Bushing is split so that when the locking capscrews
force bushing into tapered bore, the bushing grips
the shaft with a positive clamping fit. This will
withstand vibration and heavy loads without being
loosened.
4. Impeller and bushing assembly is keyed to the shaft
and held in place by compression, which adds
driving strength.
Before assembly, ensure shaft
and keyway are clean and
smooth. Check key size with both shaft and
bushing keyway.
5. To assemble, insert the capscrews through the
clearance holes in the bushing and install bushing
loosely into the impeller. Do not press or drive. Start
capscrews by hand, turning them just enough to
engage threads in the nylock nut. Do not use a
wrench at this time. The bushing should be loose
enough in the propeller to move freely. Slide impeller
and bushing assembly onto shaft, allowing adequate
clearance for shaft end play to prevent friction. Fit
key into keyway. Do not force impeller and bushing
onto shaft. If it does not go on easily, check shaft,
bushing, and key sizes once again.
Tighten capscrews gradually and evenly with wrench
similar to mounting an automobile wheel. Rotate a
quarter turn on each capscrew successively until
all capscrews are tight. These capscrews force the
taper bushing into the hub, which in turn compresses
the bushing onto the shaft. This makes a positive
clamping fit. The torque must not exceed the value
specified in the table.
Do not attempt to pull bushing
flange flush with hub end.
There should be a clearance which varies
approximately 3/16-in to 1/4-in with the bushing
size when tightened. This is not a locating
dimension.
Impeller Assembly Removal
1. Remove all capscrews from impeller and hub
assembly.
2. Insert capscrews into the threaded holes in the
bushing flange.
3. Tighten each bolt in quarter of a turn increments to
push the impeller off the bushing. This forces the
bushing loose from the propeller hub and releases
the compression so that the entire assembly will
slide from the shaft.
4. Pull the bushing off the shaft.
If the assembly has been in place
sometime it may be necessary
to use a wheel puller to remove the bushing.
Never use a wheel puller on the impeller.
Split Taper
Bushing
C
A
E
D B
A. External key, except G, H and Idler Bushings
B. Bushing barrel and Product bore are tapered
C. Bushing cap screws
D. Bushing barrel is split (except idler bushings)
E. Removal holes are threaded, installation holes are not
Hub of blower wheel
or pulley
Spilt Taper Bushing Installation
Browning
®
is a registered trademark and Split Taper™ is a trademark of Emerson Power Transmission Manufacturing, L.P.
