Page 85 - 1_usa.qxp

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Calculate belt width
A belt width of 50 mm is selected .
The belt width is verified according to the peak torque (starting
torque) for n = 0 with 1,4 x 250 Nm as start up torque
The next belt width 85 mm is chosen.
Verify allowable tensile load
Calculate pulley diameter
From the maximum allowable pulleys diameter, the drive ratio
and the type of belt selected, the number of teeth of the driver
and driven pulley is calculated.
58,9 - select z = 56 with dw = 142,60 mm
The maximum allowable diameter is chosen to minimize belt
width.
z1 = 56
z2 = 56
Calculate belt length
Calculate teeth in mesh
Being the drive ratio 1, the pulleys have 28 teeth in mesh.
ze = 28
From the technical data for ELA-flex SD™ belts HTD 8M, the maxi-
mum allowable tensile load for belt width 85 mm is: 13400 N.
FTzul = 13400 N > FTV + FU = 3272,55 + 4908,83 = 8181,38 N
Verify flexibility
The minimum pulley diameters are respected.
Select belt type and pitch
From HTD selection graphs and the corrected power of 28 Kw, a
8M pitch is chosen.
- Power to be transmitted 20 Kw
- Driver rpm n1 1500 1/min
- Driven rpm n2 1500 1/min
- Motor torque M 250 Nm
- Required center distance A 1800 mm
- Max allowable driver pulley diameter dw 150 mm
- Safety factor c1 1,4
Calculate drive ratio
Calculation example
tzA2 d A2 L
w R ⋅ + ⋅ = ⋅π+ ⋅ =
mm 4048 856 1800 2 L
R = ⋅ + ⋅ =
1
n
n
2
1 = mm6,48 cm 86,4
572 ,812 56
4,120 1000
b = =
⋅ ⋅
⋅ ⋅
=
=π⋅ =
8
150
z
N83, 4908
6, 142
350 2000
FU = ⋅ =
Determine installation tension according to belt number of
teeth
zR = = 506 teeth
The installation tension per belt side FTV is therefore:
FTV = • FU = 3272,55 N with zR = 506 > 150
8
4048
3
2
mm 55= cm53,5=
422 ,912 56
4,1 250 10
=b
• •
• •