Introduction to V-Belts. Construction of V-Belts. Types of Standard Cross Section of V-Belts. Designation of V-Belts. Advantages of V-Belts & Limitation of V-Belts. Application of V-Belts.

1. Government Engineering College - Bhuj
A presentation on subject of
Design of Machine Element
&
Topic is
“V - Belts”
UMANG PARMAR

2. Content……
 Introduction to V-Belts.
 Construction of V-Belts.
 Types of Standard Cross Section of V-Belts.
 Designation of V-Belts.
 Advantages of V-Belts & Limitation of V-Belts.
 Application of V-Belts.

3. Introduction…...
• The cross section of V-belts are trapezoidal as shown in fig.
• When the two pulleys are close to each other, this type of belt drive is
used.
• In V-belt drives, the pulleys are provided with grooves. It is known as
grooved pulley or Sheaves.

4. Construction of V-Belts…...
• As shown in fig. the central load
carrying textile, nylon or steel
cords.
• Surrounding rubber to transmit
pressure from cords to side
walls.
• And the outer wall is of fabric
and rubber cover.
• The belts are made endless.

5. Construction of V-Belts…...
• The belts run in sheaves.
• The included angle for V-belt is 40ο .
• The pulley groove angle is 38o.
• The power is transmitted due to the wedging
action between the belt and the side of the
pulley groove.
• A clearance must be provided between the
bottom of the belt and the pulley groove.
• To improve the capacity for large power
transmission, multiple belts may be used.
• For heavy duty application, 12 or more belts
may be used for transmission.

6. Standard Cross Section of V-Belts……
• Based on cross sectional sizes, they are classified in six standard types.
• They are ‘Z’, ‘A’, ‘B’, ‘C’, ‘D’, ‘E’.
• The cross section area of the types are in ascending order.
Belt Section Width ‘b’ mm
Thickness ‘t’
mm
Min. pitch dia of
pulley ‘d’, mm
Correction ‘δ’
mm
Z 10 6 85 30
A 13 8 75 36
B 17 11 125 43
C 22 14 200 56
D 32 19 315 79
E 38 23 500 92

7. Designation of V-Belts……
• V-belts are designed by the symbol of cross section with the inside
length of the belt in mm.
• The relation between pitch length and inside length of V-belts is
written as follow:
Pitch Length = Inside length + correction
(L) (Li) (δ)
• For example, E 3333 is having C-section belt and 3333 mm inside
length.

8. Advantages and limitation of V-Belts…
Advantages
• They can transmit large power
due to wedging action as
compared to flat belts.
• They have short centre distance,
it helps in compact construction.
• At high operating speed, the
operation is smooth because the
belts are endless.
• The slip is negligible in V-belts.
• V-belt drive permit high
reduction ratio up to 7:1.
Limitation
• The efficiency of V-belts is less
than that of the flat belts.
• It fluctuates in the range of
80% - 90%.
• They are costlier than flat belts
because of their design.
• They can’t be used to transmit
the power over the long centre
distance.

9. Application of V-Belts……
• They are used in motors to
drive blowers, compressors,
machine tools, farm and
industrial machinery.
• Most common use of V-belt
drive in the internal combustion
engine.
• The other uses of V-belt drive
are in automobiles to drive the
accessories.

11. Thank you