Gast SDR6 - Manual (Page 4)

4
Belt Tensioning and Alignment
Fig. 1 shows how a straight edge tool should be used to
avoid parallel or angular misalignment. Table 1 shows the
force needed on the electric motor shaft to properly
tension the belt drive when the belt is installed. This table
also shows the small force needed to cause 1/4” of
deflection in the belt, see Fig 2. This is used to check belt
tension in new drives or those in service.
CAUTION:
Do not over tighten belt as it will cause
misalignment and could lead to premature failure.
PROPER ALIGNMENT WITH STRAIGHT EDGE TOOL
TOOL
PARALLEL MISALIGNMENT
TOOL
ANGULAR MISALIGNMENT
TOOL
DRIVE ALIGNMENT
FIGURE 1
C
L
C
L
C
L
Belt Tensioning and Alignment (cont.)
We strongly suggest using a Gates Poly Chain Drive. It
has been properly engineered for this type of application.
If you choose to use a “V” belt drive, the sheave on the
blower must be less than 4” in outside diameter. This
sheave should be mounted on the shaft such that it will
not block air from entering the blower cooling fan (we
recommend this high speed belt drive be engineered
following the belt drive manufacturers recommendations).
To avoid annoying vibration and noise, both sheaves
should be dynamically balanced and fit snugly on the
shaft.
Gates “Poly Chain” Belt Tensioning Requirements
Gast Blower Required pull Force to deflect Gates Poly
on motor shaft belt 1/4” with Chain Belt
for correct new belt drive/ Part#
installation Low limit for
broken in drive
SDR4 66 lbs. 3.5/2.8 lbs 8M-1000-12
DEFLECTION 1/4 INCH
FIGURE 2