GAS COMPRESSORS / BOOSTERS
GAS & AIR MIXING SYSTEMS
AIR BLOWERS & VACUUM PUMPS
The Utile Engineering Co. Ltd.
Irthlingborough, Northamptonshire, NN9 5UG, ENGLAND
Telephone: + 44 (0) 1933 650216 Facsimile: + 44 (0) 1933 652738 Email: [email protected]
www.utileengineering.com
Feb-19
11
IC013 Rev2
Correct pulley alignment
Span Distance
Fig.5
Drive Belts
1.
Remove 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. 5). Pulley angular misalignment should not exceed 1/2° and axial misalignment of
5mm/metre drive centre.
3.
When the pulleys have been correctly positioned on the shafts, belts can be installed. The
drive centre distance should be reduced by at least the minimum belt installation allowance
shown in the table below. Under no circumstances should belts be prised into the grooves,
as belts and pulleys can be damaged by tools stretching the belts over the rim of the pulley.
4.
Fit driving belts. Spin the pulleys 3-4 revolutions to bed belts into the pulley grooves. (Note:
if done manually, beware of finger entrapment between belts and pulleys). Measure span of
belts between tangent points of the two pulleys. A deflection of 16mm is obtained for every
1metre of the measured span. Check the deflection force required with the table below. If
the force required is according to the table then the tension is suitable. Too little force
indicates under-tension and visa-versa.
5.
New drive belts should be tensioned as per the “new drive tension column” in the table, run
the drive under load for 30 minutes. Stop the drive, check the tension and reset to the “normal tension” in the table. Belt
tension and condition should be checked daily in the first week after installation/renewal, and regularly thereafter. On
packaged units (where Utile supply the motor and machine), the recommended belt tension is shown on/next to the guard.
Belt Section
Setting force required to deflect belt 16mm per metre of span
Minimum belt
installation
allowance (mm)
Small Pulley
diameter (mm)
Normal Tension
New drive Tension
Newtons (N)
Kilograms (kgf)
Newtons (N)
Kilograms (kgf)
SPZ
56 to 71
16
1.6
20
2.0
20
75 to 90
18
1.8
22
2.2
95 to 125
20
2.0
25
2.5
Over 125
22
2.2
28
2.8
SPA
80 to 100
22
2.2
28
2.8
25
106 to 140
30
3.0
38
3.9
150 to 200
36
3.7
45
4.6
Over 200
40
4.1
50
5.1
SPB
112 to 160
40
4.1
50
5.1
30
170 to 224
50
5.1
62
6.3
236 to 355
62
6.3
77
7.9
Over 355
65
6.6
81
8.3
SPC
224 to 250
70
7.1
87
8.9
50
265 to 355
92
9.4
115
11.7
Over 375
115
11.7
144
14.7
Belt Section
Setting force
per rib
required to deflect belt 16mm per metre of span
Minimum belt
installation
allowance (mm)
Small Pulley
diameter (mm)
Normal Tension
New drive Tension
Newtons (N)
Kilograms (kgf)
Newtons (N)
Kilograms (kgf)
PJ
below 45
1.6
0.16
3.0
0.31
20
45 to 66
3.0 to 5.0
0.30
5.0
0.51
67 to 125
4.0 to 7.0
0.40
7.0
0.71
PL
below 160
10 to 15
1.0
15
1.5
28
160 to 224
12 to 20
1.2
20
2.0
Warning:
Always replace belts in matched sets.
Excessive tension on the pulleys will damage the bearings and lead to a probable shaft rupture.
Belt speed must
NOT
exceed 30m/s.
Belts must comply with BS ISO1813:2014 and BS ISO9563:2015.
Belts, which become charged electrostatically, must not be used in hazardous atmospheres.
Installation - Drive
