CAMCORP Blower Package with Roots Blower - Manual (Page 27)

4 For your nearest Roots Office, dial our Customer Service Hot Line 1 877 363 ROOTS (7668).
least 1 inch (25 mm) thick, with its top surface
machined flat, and large enough to provide leveling
areas at one side and one end after the unit is mount-
ed. It should have properly sized studs or tapped holes
located to match the unit foot drilling. Proper use of a
high quality machinist’s level is necessary for adequate
installation.
With the mounting plate in place and leveled, set the
unit on it without bolting and check for rocking. If it is
not solid, determine the total thickness of shims
required under one foot to stop rocking. Place half of
this under each of the diagonally-opposite short feet,
and tighten the mounting studs or screws. Rotate the
drive shaft to make sure the impellers turn freely. If the
unit is to be direct coupled to a driving motor, consider
the height of the motor shaft and the necessity for it to
be aligned very accurately with the unit shaft. Best unit
arrangement is directly bolted to the mounting plate
while the driver is on shims of at least 1/8 inch (3mm)
thickness. This allows adjustment of motor position in
final shaft alignment by varying the shim thickness.
Aligning
When unit and driver are factory mounted on a
common baseplate, the assembly will have been
properly aligned and is to be treated as a unit for
leveling purposes. Satisfactory installation can be
obtained by setting the baseplate on a concrete slab
that is rigid and free of vibration, and leveling the top
of the base carefully in two directions so that it is free
of twist. The slab must be provided with suitable anchor
bolts. The use of grouting under and partly inside the
leveled and shimmed base is recommended.
It is possible for a base-mounted assembly to become
twisted during shipment, thus disturbing the original
alignment. For this reason, make the following checks
after the base has been leveled and bolted down.
Disconnect the drive and rotate the unit shaft by hand.
It should turn freely at all points. Loosen the unit foot
hold-down screws and determine whether all feet are
evenly in contact with the base. If not, insert shims as
required and again check for free impeller rotation.
Finally, if unit is direct coupled to the driver, check
shaft and coupling alignment carefully and make any
necessary corrections.
In planning the installation, and before setting the unit,
consider how piping arrangements are dictated by the
unit design and assembly. Drive shaft rotation must be
established accordingly and is indicated by an arrow
near the shaft.
Typical arrangement on vertical units has the drive
shaft at the top with counterclockwise rotation and
discharge to the left. Horizontal units are typically
arranged with the drive shaft at the left with counter-
clockwise rotation and discharge down. See Figure 3
and 4 for other various unit arrangements and
possible conversions.
When a unit is DIRECT COUPLED to its driver, the
driver RPM must be selected or governed so as not to
exceed the maximum speed rating of the unit. Refer to
Table 1 for allowable speeds of various unit sizes.
A flexible type coupling should always be used to
connect the driver and unit shafts.
Coupling halves must be accurately aligned, and a
sufficient gap between shaft ends provided so that side
strains and end thrust on either shaft are avoided or
minimized. This will require considerable care in the
mounting of the driver. The two shafts must be in as
near perfect alignment in all directions as possible, and
the gap must be established with the motor armature
on its electrical center if end-play exists.
The following requirements of a good installation are
recommended. Coupling halves must be fitted to the
two shafts with a line to line thru .001” interference fit.
Coupling halves must be warmed up, so that only light
tapping is required to install them. Maximum deviation
in offset alignment of the shafts should not exceed
.005” (.13 mm) total indicator reading, taken
on the two coupling hubs. Maximum deviation from
parallel of the inside coupling faces should not exceed
.001” (.03 mm) when checked at six points around
the coupling.
When a unit is BELT DRIVEN, the proper selection of
sheave diameters will result in the required unit speed.
This flexibility can lead to operating temperature prob-
lems caused by unit speed being too low. Make sure
the drive speed selected is within the allowable range
for the specific unit size, as specified under Table 1.
Belt drive arrangements usually employ two or more
V-belts running in grooved sheaves. Installation of the
driver is less critical than for direct coupling, but its
shaft must be level and parallel with the unit shaft.
The driver should be mounted on the inlet side of
a vertical unit (horizontal piping) and on the side
nearest to the shaft on a horizontal unit. 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.
Install the unit sheave so that its inner hub face is not
more than 1/8 inch (3mm) from the drive end cover.
See page 18 for minimum sheave diameter and
maximum sheave width. The shaft fit should be such
that the sheave can be worked into place by hand or
by very light tapping. A tight or driving fit can damage
a bearing, and may cause internal unit damage by
forcing the impeller out of its normal operating position.
A loose fit or wobbly sheave will cause vibration, and
may result in shaft breakage.
CAUTION: Couplings as well as sheave bushings
must have a slight slide fit with the unit shaft such
that they can be installed in place by hand. Any force
used to install them could change unit end clearance
resulting in unit damage. If interference fit is desired for
the coupling, the coupling hub should be heated and
shrunk on the shaft. For engine drives, use “locktite”
between the coupling hubs and the shafts and on the
threads of the coupling set screws.