Howden Roots Metric Series, Инструкция по установке, эксплуатации и обслуживанию, Страница: 6 / 32

ISRB_2002 GEA 19171 Roots URAI Page 6 of 32
Blower Drive Arrangement Options. The driver must
also be mounted on an adjustable base to permit
installing, adjusting and removing the V-belts. To
position the driver correctly, both sheaves need to be
mounted on their shafts and the nominal shaft center
distance known for the belt lengths to be used.
CAUTION:
Drive couplings and sheaves (pulleys)
should have an interference fit to the shaft of the blower
(set screw types of attachment generally do not provide
reliable service.) It is recommended that the drive
coupling or sheave used have a taperlock style bushing
which is properly sized to provide the correct
interference fit required. Drive couplings, that require
heating to fit on the blower shaft, should be installed per
coupling manufacturer recommendations. A drive
coupling or sheave should not be forced on to the shaft
of the blower as this could affect internal clearances
resulting in damage to the blower.
Engine drive applications often require special
consideration to drive coupling selection to avoid
harmful torsional vibrations. These vibrations may
lead to blower damage if not dampened adequately.
It is often necessary to install a fly-wheel and/or a
torsionally soft elastic element coupling based on
the engine manufacturer recommendations.
The driver sheave should also be mounted as close to
its bearing as possible, and again should fit the shaft
correctly. Position the driver on its adjustable base so
that 2/3 of the total movement is available in the
direction away from the unit, and mount the assembly so
that the face of the sheave is accurately in line with
the unit sheave. This position minimizes belt wear, and
allows sufficient adjustment for both installing and
tightening the belts. After belts are installed, adjust their
tension in accordance with the manufacturer’s
instructions. However, only enough tension should be
applied to prevent slippage when the unit is operating
under load. Excessive tightening can lead to early
bearing concerns or shaft breakage.
Before operating the drive under power to check initial
belt tension, first remove covers from the unit
connections. Make sure the interior is still clean, and
then rotate the shaft by hand. Place a coarse screen
over the inlet connection to prevent anything being
drawn into the unit while it is operating, and avoid
standing in line with the discharge opening. Put oil in the
sumps per instructions under LUBRICATION .
Piping
Before connecting piping, remove any remaining anti-
rust compound from unit connections. Clean pipe should
be no smaller than unit connections. In addition, make
sure it is free of scale, cuttings, weld beads, or foreign
material of any kind. To further guard against damage to
the unit, especially when an inlet filter is not used, install
a substantial screen of 16 mesh backed with hardware
cloth at or near the inlet connections. Make provisions to
clean this screen of collected debris after a few hours of
operation. It should be removed when its usefulness has
ended, as the wire will eventually deteriorate and small
pieces going into the unit may cause serious damage.
ISRB_2002 GEA 19171 Roots URAI.indd 6 17/09/2015 12:52