The Utile Engineering Co. Ltd.
28/07/04
Irthlingborough, Northamptonshire. England
Tel: +44 (0) 1933 650216
Fax: +44 (0) 1933 652738
7
IC101
Fitting Pulleys and Couplings
These should be bored to our standard limits (details supplied upon request) and fitted to the shaft with a screwing
motion. On no account should they be driven on. Tapping of fitments onto the machine shaft with a hammer or
mallet, causes bearing damage. This results in an increase in bearing noise and a significant reduction in bearing
life. Attention should be paid to the guarding of all moving parts.
Drive Alignment
The rotor shaft must always be horizontal. There are three basis modes of misalignment, these are angular, parallel
and axial (shown in fig. 4).
Flexible Coupling
1.
Remove any dirt, oil, etc. from all mating surfaces. Place bush in hub and
match half holes on both shafts.
2.
Place setscrews loosely in threaded holes. Mount assembly in desired
position on shafts.
3.
Tighten setscrews. Place disc/flexible coupling in position, and bring the
shafts together obtaining the manufacturers assembled length for the
coupling given in their instructions.
4.
To check for angular alignment: (see fig. 5)
Rotate the coupling through 90
°
and measure the distance between the
faces. Repeat adjusting the shafts until four identical measurements are
obtained.
To check for parallel alignment: (see fig. 5)
Place a straight edge across the coupling. The hubs will be in correct
alignment when the straight edge contacts the 4 points squarely.
Drive Belts
1.
Remove any dirt, oil, etc. from all mating surfaces. Place bush in hub and
match half holes on both shafts.
2.
Mount assembly in desired position on shafts ensuring both shafts are
parallel and in correct alignment, use a straight edge, a correctly aligned
drive will contact both pulleys squarely (see fig. 6).
3.
Fit driving belts. Measure span of belts between tangent points of the two
pulleys. A deflection of 1.5mm is obtained for
every 100mm of the measured span. Compare
the deflection force required with the table. If
the force required is according to the table
then the tension is suitable. Too little force
indicates under-tension and visa-versa.
4.
The belts should be tensioned towards the
high side, to allow for the tension drop after the belts have been run-in. Belt
tension should be checked daily in the first week after installation/renewal.
Warning
Excessive tension on pulleys will damage the bearings and lead to probable shaft rupture.
Belts, which become charged electrostatically, must not be used in hazardous atmospheres.
Belt
Section
Force Required to
deflect belt 1.5mm per
100mm span (kgf)
SPZ
0.5 to 0.8
SPA
1.0 to 1.5
SPB
2.0 to 3.1
SPC
4.1 to 6.1
Parallel Alignment Check
Angular Alignment Check
Fig. 5
Angular Misalignment
Parallel Misalignment
Axial Misalignment
Fig. 4
Correct pulley alignment
Span Distance
Fig. 6
Installation
