V-Belts are the very most common type of belt drive used for power transmission. Their important function is to transmit power from a one primary source, like an electric motor, to a secondary unit. They provide the excellent combination of traction, speed transfer, load distribution, and extended service life.

1. V-Belt Drive
Design Procedure-Design Data

2. Design
Using manufacturers data
Using Basic equations
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3. Design Procedure
Selection of belt
cross section
Selection of pulley
diameters
(D and d)
Selection of centre
distance (C)
Determination of
nominal pitch
length
Selection of various
modification
factors
Calculation of
maximum power
capacity
Determination of
number of belts
Calculation of
actual centre
distance
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4. Selection of Belt cross Section
• Select the cross section of the belt (ie Type of belt) depending on
the power to be transmitted (PSG Data Book Pg No 7.58)
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Cross Section
Symbol
Area
mm2
Usual load of
drive
kW
Recommende
d minimum
pulley pitch
dia (d)
mm
Nominal top
width (w)
mm
Nominal
Thickness (T)
mm
Mass per
metre (m)
kg/m
A 80 0.75-5 75 13 8 0.106
B 140 2-15 125 17 11 0.189
C 230 7.5-75 200 22 14 0.343
D 475 22-150 355 32 19 0.595
E 695 30-190 500 38 23 -

5. Selection of Pulley Diameter (d and D)
• Select small pulley diameter from table (PSG Data Book Pg No
7.58)
• Using Speed ratio find maximum diameter
• Round off to the nearest standard diameter
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6. Selection of Centre Distance
Select the centre distance (PSG Data Book Pg No 7.61)
𝐶𝑚𝑖𝑛 = 0.55 𝐷 + 𝑑 + 𝑇
𝐶𝑚𝑎𝑥 = 2 (𝐷 + 𝑑)
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7. Determination of Nominal Pitch length
𝑳 = 𝟐𝑪 +
𝝅
𝟐
𝑫 + 𝒅 +
(𝑫 − 𝒅)𝟐
𝟒𝑪
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For pitch length add with inside length
36 mm for A Belt
43 mm for B Belt
56 mm for C Belt
79 mm for D Belt
92 mm for E Belt

8. Selection of various modification factors
Length correction factor
(PSG Data Book Pg no = 7,.58,7.59,7.60)
Arc of contact correction factor
(PSG Data Book Pg no = 7.68)
Service factor
(PSG Data Book Pg no = 7.69)
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9. Calculation of Maximum power capacity
Maximum power capacity
(PSG Data Book Pg No 7.62)
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10. Determination of no of Belts
𝒏𝒃 =
𝑷 ∗ 𝑭𝒅
𝒌𝑾 ∗ 𝑭𝒄 ∗ 𝑭𝒅
PSG Data Book Pg no = 7.70
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11. Calculation of Actual Centre Distance
𝐶𝑎𝑐𝑡𝑢𝑎𝑙 = 𝐴 + 𝐴2 − 𝐵
𝐴 =
𝐿
4
− 𝜋
𝐷 + 𝑑
8
𝐵 =
(𝐷 − 𝑑)2
8
L=Nominal pitch length of the belt from table (Step 5)
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12. B.Varun
9787608011
bvarun.me@gmail.com
varun.me@srit.org
varunnelson bvarun.me
varunme bvarunme
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