Advantages and Disadvantages of V-belt Drive over Flat Belt Drive

Following are the advantages and disadvantages of the V-belt drive over flat belt drive :-

Advantages:-

1. The V-belt drive gives compactness due to the small distance between centers of pulleys.
2. The drive is positive, because the slip between the belt and the pulley groove is negligible.
3. Since the V-belts are made endless and there is no joint trouble, therefore the drive is smooth.
4. It provides longer life, 3 to 5 years.
5. It can be easily installed and removed.
6. The operation of the belt and pulley is quiet.
7. The belts have the ability to cushion the shock when machines are started.
8. The high velocity ratio (maximum 10) may be obtained.
9. The wedging action of the belt in the groove gives high value of limiting *ratio of tensions.
Therefore the power transmitted by V-belts is more than flat belts for the same coefficient of
friction, arc of contact and allowable tension in the belts.
10. The V-belt may be operated in either direction, with tight side of the belt at the top or
bottom. The center line may be horizontal, vertical or inclined.

Disadvantages:-

1. The V-belt drive can not be used with large center distances, because of larger weight per
unit length.
2. The V-belts are not so durable as flat belts.
3. The construction of pulleys for V-belts is more complicated than pulleys of flat belts.
4. Since the V-belts are subjected to certain amount of creep, therefore these are not suitable
for constant speed applications such as synchronous machines and timing devices.
5. The belt life is greatly influenced with temperature changes, improper belt tension and
mismatching of belt lengths.
6. The centrifugal tension prevents the use of V-belts at speeds below 5 m/s and above 50 m/s.