37-1-614 Page 12
Inlet Filter or Filter-Silencer
– For pressure service handling air, the blower inlet must be protected by a
filter of suitable size to allow full flow of air to the blower inlet. The filter must be of adequate efficiency to
trap any foreign materials which may be in the general area of the air inlet. If noise is a factor, filter-
silencers are available.
Rotating components will cause severe injury in case of personal contact. Keep hands away
from the blower inlet and discharge ports.
In choosing a location for the filter, consideration should be given to a source of cool, clean air, and most
important, access for maintenance.
Filters generally used for blower service fall under three types:
Oil-wetted Screen Type
Oil Bath
Dry Type
Filter-silencers are also available in the above types.
For vacuum service, the type of system used and materials being handled will determine the necessity for
an in-line filter.
Couplings
– For direct-coupled units, a flexible type coupling, accurately aligned, should be used
between the blower and power unit. A grid type coupling is recommended. Misaligned couplings may
cause vibration, additional bearing loads and stresses which will affect life of parts involved. DO NOT
drive the couplings on shaft. Check shaft and coupling bore for burrs. Polish the shaft and bore if
necessary for proper fit. Fit keys to keyways. Check coupling alignment. Exact alignment will vary with
the type of couplings; however, it is not uncommon to hold alignment within .003” in all directions. With
lubricated or special couplings, follow the manufacturer’s instructions for installation and maintenance.
Do not use couplings that may cause an axial thrust during operation.
DRIVE INSTALLATION
V-Belt Drive
– Follow normal specifications recommended by the belt manufacturers for installation of
belt drive on blowers. To provide the most compact drive, it is suggested that high capacity V-belt drives
be used. Blower shaft and power unit shaft should be parallel, with sheaves aligned on shafts so belts
run true. Use only matched belt sets and replace belts in complete sets only. Belt tension should be
according to manufacturer’s recommendations. Slippage can be detected by belt squeal, overheating or
loss of speed. A few hours after initial starting with new belts, it is advisable to recheck belt tension and
provide tension adjustment as necessary.
Over tightening belts leads to heavy bearing loads and premature failure.
When selecting a V-belt drive, check to be sure the maximum allowable moment limitation is not
exceeded. Refer to (Figure 2-3 page 14), for V-belt drive overhung load calculations. (Figure 2-3),
applies to V-belt calculations only. Exceeding overhung load limitations leads to premature bearing
failure and potential shaft breakage.
