Tuthill PD Plus 1215 - Motor Drives; Direct Coupled; V-Belts

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5.6 MOTOR DRIVES
Two drive connections commonly used are direct drive and V-belt drive.
5.6.1 DIRECT COUPLED
When installing the motor directly to the blower, align shafts to coupling in accordance with the coupling
manufacturer’s instructions. Blowers shipped with motor directly coupled and mounted on a common base
have been aligned prior to shipment and normally no further alignment is necessary. However, alignment
should be checked and adjustments made if necessary prior to starting the unit.
Coupling halves must correctly t the blower and drive shafts so that only light tapping is required to install
each half. The two shafts must be accurately aligned, A direct coupled blower and motor must be aligned
with the two shafts not having more than .005” (13 mm) T.I.R. (Total Indicator Reading). Face must be
aligned within .002”(.05 mm) .
Proper gap between coupling halves must be established according to coupling manufacturers instructions
with the motor armature. This will minimize the change for end thrust on the blower shaft. All direct coupled
base mounted units must be re-aligned and greased after eld installation.
5.6.2 V-BELTS
If the motor and blower are V-belt connected, the sheaves on both motor and blower shafts, should be as
close to the shaft bearings as possible. Blower Sheave is not more than 1/4” (6.5 mm) from the blower
drive end cover. The drive sheave is as close to the driver bearing as possible. Care should be taken when
installing sheaves on the blower and motor shafts. The face of the should be accurately in line to minimize
belt wear.
Adjust the belt tension to the to the manufactures specications using a belt tension tester. New belts should
be checked for proper tension after 24 hours of run time. When manufacturer data is not available industry
guidelines are 1/64 inch deection for each inch of span at 8 to 10 pounds of force in the center of the belt.
Insufcient tensioning is often indicated by slipping (squealing) at start up. Belt dressing should not be
used on V-belts. Sheaves and V-belts should remain free of oil and grease. Tension should be removed
from belts if the drive is to be inactive for an extended period of time. For more specic information consult
the drive manufacturer. In a v-belt drive, the blower sheave must t its shaft accurately, run true, and be
mounted as close to the bearing housing as possible to minimize bearing loads.
A tight or driving t will force the drive shaft out of its normal position and cause internal damage. A loose
t will result in shaft damage or breaking. The motor sheave must also t correctly and be properly aligned
with the blower sheave.
Adjust motor position on its sliding base so that belt tension is in accordance with drive manufacturer’s
instructions. Avoid excessive belt tension at all times. Recheck tension after the rst ten hours of operation
and periodically thereafter to avoid slippage and loss of blower speed.
Check blower after installation and before applying power by rotating the drive shaft by hand. If it does not
rotate freely, look for uneven mounting, piping strain, excessive belt tension, or coupling misalignment.
Check blower at this time to insure oil was added to the reservoirs.