Industrial Power Transmission Products - Bando USA

The key to long, efficient, trouble-free belt operation is proper tension. If belts are too loose, the result is slippage, rapid
belt and sheave wear and excessive “down time.” Conversely, too much tension imposes excessive strain on belts,
bearings and adjacent drive components, resulting in premature wear of one or all of the drive parts. The proper tension
is the lowest tension at which the belt(s) won’t slip or “squeal” under peak load.
Tensioning Procedures
1. Measure the span length (L) in Fig. 1.
2. At the center of the span (L) apply a force perpendicular to the belt
measuring the force needed to deflect the belt 1/64" per inch of span
length (L).
3. Compare the force required in step 2 to the recommended range(s) in the
appropriate table(s). Tighten or loosen the belt tension to bring the
tension into the recommended range.
4. For V-belts, run the drive for five (5) or ten (10) minutes to seat the belt
and then recheck the tension.
5. For timing belts, the belt should fit snugly – neither too tight nor too loose.
The “tooth grip” eliminates the need for high initial tension.
Span Length, L
V-Belt Drives
Recommended Deflection Force (Lbs.)*
Recommended Deflection Force (Lbs.)*
V Belt
Cross
Section
Small Pulley
Diameter Range
(Inches)
Initial
Installation
Retensioning
Maximum Minimum
V Belt
Cross
Section
Small Sheave
Diameter Range
(Inches)
Initial
Installation
Retensioning
Maximum Minimum
2.65 - 3.35
3.65 - 4.50
4.75 - 6.0
6.5 - 10.6
4.6
5.5
6.4
7.3
4.0
4.8
5.6
6.4
3.1
3.7
4.3
4.9
7.1 - 10.3
10.9 - 11.8
12.5 - 16.0
16.5
19.5
21.0
14.3
16.9
18.2
11.0
13.0
14.0
12.5 - 16.0
17.0 - 20.0
21.2 - 24.4
39.0*
45.0*
51.0*
33.8*
39.0*
44.2*
26.0*
30.0*
34.0*
2.2 - 2.5
2.65 - 4.75
5.0 - 6.5
6.9 -
- 5.5
5.9 - 8.0
8.5 - 10.9
11.8 -
- 3.0
3.1 - 4.0
4.1 - 5.0
5.1 -
- 4.6
4.7 - 5.6
5.7 - 7.0
7.1 -
- 7.0
4.8
5.7
7.2
8.7
15.0
19.0
21.0
22.0
5.1
5.5
6.0
6.7
10.0
11.0
11.5
12.0
18.0
4.2
4.9
6.2
7.5
13.0
16.9
18.2
19.5
4.4
4.8
5.2
5.9
8.7
9.5
9.9
10.1
15.6
3.2
3.8
4.8
5.8
10.0
13.0
14.0
15.0
3.4
3.7
4.0
4.5
6.7
7.3
7.6
7.8
12.0
7.1 - 9.0
9.1 - 12.0
19.5
20.0
16.9
17.6
13.0
13.5
Belt Size 012 019 025 031 037 050
Belt Width 1/8" 3/16" 1/4" 5/16" 3/8" 1/2"
Max. .10 .15 .24 .35 .42 .62
MXL
Min. .05 .09 .13 .19 .22 .33
075
3/4"
100
1"
150 200 300
11/2" 2" 3"
400
4"
500
5"
600
6"
12.1 21.0 18.2 14.0
12.5 - 16.0 62.4 54.1 41.6
17.0 - 20.0 72.0 62.4 48.0
21.2 - 24.4 81.6 70.7 54.4
XL
Max.
Min.
.42
.20
.55
.31
.66
.37
1.1
.57
1.9
1.0
Rib Ace
L
H
Max.
Min.
Max.
Min.
1.3
1.0
2.1
1.5
4.7
3.7
2.9
2.2
6.8
5.2
4.7 6.4
3.4 4.7
10.4 14.3 22.4
8.2 11.2 17.6
Belt Cross Section
Small Sheave
Diameter Range
Force “F”
Lbs./Rib
XH
Max.
Min.
17.7 27.9 39.7 51.0
16.3 25.8 36.7 47.0
62.2
57.3
Max.
XXH
Min.
40.5 63.9 90.7 117.2 142.1
21.5 34.0 48.1 62.3 75.2
For tensioning information on STS and HT constructions refer to pages 72 and 77.
For complete drive installation, maintenance and troubleshooting instructions, request Bando publication BU-106 (V-Belt and
Timing Belt Installation and Maintenance) or download Publication BU-106 at www.BANDOUSA.com.
® A
- 3.0
3.1 - 4.0
4.1 - 5.0
5.1 -
3.6
4.2
5.2
6.1
3.1
3.6
4.6
5.3
2.4
2.8
3.5
4.1
3V
B
- 4.6
4.7 - 5.6
5.7 - 7.0
7.1 -
7.3
8.7
9.3
10.0
6.4
7.5
8.1
8.8
4.9
5.8
6.2
6.8
5V
C
- 7.0
7.1 - 9.0
9.1 - 12.0
12.5
15.0
18.0
10.7
13.0
16.3
8.2
10.0
12.5
8V
12.1 - 19.5 16.9 13.0
12.0 - 13.0 25.5* 22.1 17.0
D 13.1 - 15.5 30.0* 26.0* 20.0
15.6 - 22.0 32.0* 28.0* 21.5
E 18.0 - 22.0 45.0* 39.0* 30.0*
22.1 - 52.5* 45.5* 35.0*
1.5 - 2.0 1.4 1.1 0.8
3L 2.1 - 2.7 1.9 1.4 1.1
2.8 - 4.0 2.5 2.0 1.5
2.0 - 2.5 2.1 1.6 1.2
4L 2.6 - 3.5 2.4 1.8 1.4
3.6 - 5.0 3.1 2.3 1.8
3.0 - 3.5 3.2 2.5 1.9
5L 3.6 - 4.5 4.1 3.2 2.4
4.6 - 6.0 5.1 3.9 3.0
* For banded belts, multiply the force in the table
by the number of belts in the band.
3VX
5VX
AX
BX
Timing Belt Drives
Units are lbs. CX
8VK
* For smaller gauges, use 1/2 the value in the
table and calculate deflection distance at
1/128th inch per inch of span length.
Drives
J
J
J
1.32 - 1.67
1.77 - 2.20
2.36 - 2.95
0.4
0.5
0.6
L
L
L
2.95 3.74
3.94 - 4.92
5.20 - 6.69
1.7
2.1
2.5
M
M
M
7.09 - 8.82
9.29 - 11.81
12.40 - 15.75
6.4
7.7
8.8
Force
Fig. 1
To find an authorized BANDO distributor, go to www.bandousa.com or call 1-800-829-6612
Deflection
1/64" per
inch of span
133
Tensioning Information