GLOBEAIRE RDD Manual De Instalación, Operación Y Mantenimiento página 20

Tapered Bushing Hub Installation and
Removal
For wheel hubs and shaft pulleys utilizing a tapered
bushing interface, follow this procedure for installation
and removal. There are two possible set ups for the
tapered bushing, both have the same procedure, but
orientation of the hub varies.
Tapered Bushing Removal:
1. (If present): Loosen the setscrew holding the bushing
and shaft key in place.
2. Loosen and remove the socket head cap screws
fastening the bushing to the hub as shown in the
section views and examples of Figures 13-16.
Standard Mounting
Figure 13
Bushing
Hub
Washers
Cap Screws
Hub
Bushing
Washers
Figure 15
Cap Screws
Standard Bushing Orientation
3. Standard Mounting: Take the two socket head cap
screws that were removed and install them into the
visibly threaded holes on the wheel hub.
Reverse Mounting: Install the two socket head cap
screws into the visibly threaded holes of the bushing
flange.
8 Roof Mounted Downblast Fans
Reverse Mounting
Bushing
Hub
Washers
Cap Screws
Figure 14
Hub
Bushing
Washers
Cap Screws
Figure 16
Reverse Bushing Orientation
4. Once both socket head cap screws are installed,
tighten them an eighth of a turn at a time, alternating
between the two until the hub loosens from the
bushing.
Bushing Installation:
1. Clean all surfaces of hub and bushing to remove any
oil or residue present and do not use any lubricant to
install bushing into the hub. For both standard and
reverse mounting styles, the socket head cap screws
are adjustable from the inlet of the fan.
2. Standard Mounting: Slide the bushing and shaft
key onto the fan shaft followed by the wheel and hub
assembly. If present, use the keyway setscrew to
hold the shaft key and bushing in place but DO NOT
overtighten as this can damage the bushing. Align
the unthreaded holes of the hub with the threaded
holes of the tapered bushing.
Reverse Mounting: Slide the wheel and hub
assembly onto the fan shaft followed by the bushing
and shaft key. If present, use the keyway setscrew to
hold the shaft key and bushing in place but DO NOT
overtighten as this can damage the bushing. Align
the unthreaded holes of the tapered bushing with the
threaded holes of the hub.
3. Install the two bushing socket head cap screws
into the aligned holes by hand (or without excessive
torque) until the heads of the socket head cap
screws are seated against the mating surface.
4. Adjust the height of the wheel in the fan relative to
the inlet venturi then tighten the two socket head
cap screws an eighth turn at a time in an alternating
fashion and to a torque of 10 ft-lbs.
Belt and Bearing Maintenance RDB Unit
1. Belts tend to stretch after a period of time. They
should be checked periodically for wear and
tightness. When replacing belts, use the same type
as supplied with the unit.
2. Matched belts should always be used on units with
multi-groove pulleys.
3. For belt replacement, loosen the tensioning device
enough to allow removal of the belt by hand.
4. Once installed, adjust belts as shown in
"Pre-Starting Checks."
5. To ensure tightness, check pulley setscrews. Proper
keys must be in keyways.
6. Fan RPM should not be readjusted. Only use
pulleys of identical size and type when replacing
pulleys.
7. Shaft bearings can be classified in two
groups: relubricating and non-relubricating. All
non-relubricating bearings on model RDB fans are
factory lubricated and require no further lubrication
under normal use (between -20º to 180ºF (-29º to
82ºC) in a relatively clean environment).
8. On RDB belt driven fans, the standard cast pillow
block bearings are factory lubricated and are