3
6.0 Maintenance
1. A time schedule should be established for inspection of rotating
parts in the exhauster. The frequency of inspection must be
determined by the severity of operation and the locality.
Proper bearing lubrication is of major importance in the continued,
efficient operation of the AAF Type K Exhauster. Generally, the
following should be taken into consideration when lubricating fan or
motor bearings.
a. A reasonable periodic lubrication schedule should be instituted
after some maintenance experience on the unit is gained.
Frequency of lubrication will depend upon air temperature,
amount of dust in the air, and moisture or corrosive content of
the environment.
b. The proper type lubricant should be particularly noted. See
specific instructions in service envelope. The factory grease is
Chevron SRI #2 or equal.
c. Care should be taken not to over lubricate the bearing as this will
cause high temperature operation. When lubricating bearings
with a pressure grease gun, care should also be taken so
bearing seals are not damaged.
2. Housing and wheel should be inspected periodically, through the
inspection door, for wear and possible accumulation of dust.
Various methods of cleaning may be employed depending on the
particular installation.
Two most common methods are:
a. Steam, water, or air under high pressure.
b. Manual wire brush cleaning or scraping.
This cleaning is necessary where dust has accumulated to
prevent unbalanced conditions. Precautions should be taken to
make sure bearings and motor are protected when any high
pressure method of cleaning is used.
All bolts should be periodically inspected and tightened.
Force
Deflection
Belt Span
3. Belt Driven Units—V-belt drives should be checked on a regular
basis to determine if proper alignment and tension are being
maintained. It is recommended that belts be replaced in matched
sets when necessary.
7.0 Bearings
The Type K Exhauster is furnished with a variety of bearings
depending upon type duty, size, RPM, etc. Detailed information on the
specific bearings furnished is supplied in the service and installation
envelope attached to the exhauster at shipment. It is important that
identical bearings be used when replacement is required. (Note: The
shaft should be inspected for damage before installing new bearings.
It is often economical to replace the shaft when installing new
bearings.)
Type K Exhausters using
15
/
16
" and larger bearings are normally
supplied with one fixed and one floating bearing. A slight improvement
in bearing life is normally achieved by keeping the fixed bearing on
the outboard position.
8.0 Impeller Removal and Installation
To remove the impeller, it is necessary to first remove the front plate.
All K Exhausters are furnished with split taper hubs and bushings.
Remove the hub and bushing according to the following directions.
The impeller can then be removed through the inlet side of the scroll.
Installation is the reverse of removal.
Belt Deflection Force
Deflection Force (lbs.)
Small Sheave
A
B
Belt
Diameter
“Run-in” Period
Normal Period
3V
2.65 to 3.35
6
3 to 4
1
/
2
4.75 to 6.00
8
4 to 6
5V
7.1 to 9.00
16
8 to 12
12.5 to 16.00
20
10 to 15
8V
18.0 to 22.4
40
20 to 30
