Today we will
discuss about belt drive and its types. We all know that belt drives are used
to transmit power form one shaft to another, which have not common axis. In the
fact belt drive is used to transmit power. One alternate of belt drive is gear
drive but gear drive is not economical when large distance between driving and
driven shaft. Belt drive is very popular in power transmission due to its lower cost and high performance. They are used in many industries. The main principle of belt drive is friction. The power transmission between shaft is depend on friction between belt and pulley.
The amount of power transmitted depends upon the following
factors :-
1. Velocity of belt
2. Tension under belt placed on pulleys
3. Arc of contact between thee belt and the smaller pulley
Factor consider while selecting belt drive:-
1. Speed of the driving and driven shaft
2. Speed reduction ratio
3. Power to be transmitted
4. Center distance between shafts
5. Shaft layout
Types of belt drives:-
According to power transmitted
1. Light drives:
These are used to transmit small power at belt speed up to
about 10m/s. It is usually used in agricultural machines and small machine tools.
2. Medium drives:
These are used to transmit medium power at belt speeds from
10m/s to 22m/s. It is used in machine tools.
3. Large drive:
These are used to transmit large power at belt speeds above
22 m/s. These are used in compressor, generator and heavy machinery.
According to the arrangement of belt:
1. Open belt drive:
These belt drive used with shaft s arranged parallel and
rotating in same direction. In this drive the driver pulley pulls the belt from
one side and delivery it to the other side. Thus the power is transmitted form
driver pulley to driven pulley. The tension in the lower side of the belt is
more than the upper side. So the lower side is known as tight side and upper
side is known as slack side.
2. Crossed belt drive:
This belt drive is used when shafts are parallel to each
other but rotating in opposite direction. In this case the driver pulls the
belt form one side and delivers it the other side. In this drive tension is
more on that side where driver pulls the belt, so this side is known as tight
side and other is known as slack side.
3. Quarter turn belt drive:
This belt drive is also known as right angle belt drive. This
drive is used when shafts arranged at right angles and rotating in one definite
direction. To prevent the leaving the belt in this drive the width of face of
pulley is 1.4 times greater that the width of belt.
4. Compound belt drive:
A compound belt drive is used when power is transmitted on
more than one shaft. In this arrangement power is transmitted form one shaft to
another through a number of pulleys.
These all are main types of belt drives used in industries. If you have any query regarding this article ask by commenting.